Something that drives me right around the bend, especially when reading fantasy, is blank-slating the protagonist. Killing off the parents is very popular. Brothers and sisters too, if they exist – and it’s sad how often they don’t. If the protagonist is the long lost heir to something or other, then – like Uncle Owen and Aunt Beru – the foster-family will usually bite the dust by the end of the first chapter.
Unless they’re evil, of course. There’s the Cinderella trope, where the protagonist has no ties because her family/guardians/whatever just hate her even though she’s sweet and wonderful and beautiful and all that crap. Or the protagonist could be a loner for one reason or another, living by her wits, thieving or hunting or whatever it is she does all alone with no family ties to interfere with the story….
No, no, and hell no. This is the absolute laziest, least original protag-starter there is. It’s easier to write a tie-less character setting off on an adventure, yes, this is true. But easier is not better.
Look at Katniss. She volunteers because she loves her sister, because she has a life and ties and someone she loves enough to give up her life for. And that is so meaningful and important and the story would be utterly different if she didn’t have that intense, personal love and motivation. (I haven’t even read the damn book and I know this)
People want to connect to other people. Our herd or pack or group or whatever instinct is powerful. The NaNoWriMo group I belong to is full of people (including me) who come to regular writing events and drinking-get-togethers despite a whole rainbow of social and anxietal issues, because even the most anxious shut-in sometimes wants to hang around other people, and fellow shut-ins are kindly and safe people to hang out with who know how to cope with a panic attack.
It is vanishingly unlikely that a protagonist would have no ties at all. There are exceptions – Anna from the ‘Alpha and Omega’ stories starts out having been deliberately isolated from all outside ties by her pack, and that forced isolation is clearly presented as abusive and wrong. Nevertheless, she has made a friend whose phone she can use to call for help, and the isolation is ended in the course of the story because it’s an awful thing to do to someone. Don’t do it to your protagonist!
Dorothy Gale has a loving family she wants to get back to.
Peter, Susan, Edmund and Lucy Pevensie have parents they are forced away from by circumstances.
Spock loves his parents, but leaves to pursue a career that is meaningful to him.
Miles Vorkosigan loves his parents, as far as I know.
Nita Callahan and Kit Rodriguez have parents and siblings who are part of their daily life.
Yet somehow, their authors manage to pitchfork them into adventure anyway.
A protagonist does not and should not exist in a vacuum. Unless you’re writing a very fresh post-apocalyptic, in which whole swathes of the human population have been killed in some way or another, they shouldn’t be functioning alone – and if they are, then there needs to be a good reason for it, and a history behind it. There are ways to get rid of the family tie – youthful dedicates to a religious organization, for example, young apprentices sent away from their homes, there’s loads of ways to put parents at a distance or out of the picture. But don’t strip your protagonist of human connections altogether.
Give them friends – not just one, who can be killed off at the beginning for motivation and manpain, but more than one. Acquaintances, teachers, that annoying guy who hangs around with your group and you don’t like him but you can’t tell him to fuck off or everyone else will get mad. Nothing humanizes a character – and gives you a basis for them not being a raving sociopath – like having a place in the world. Ties to people – and to places, such as Harry’s deep love for Hogwarts – gives them that. Makes them more, for lack of a better word given that not all protagonists actually are human, human.
A good protagonist doesn’t leap from the page, blank and empty, without ties to place or person and ready to be filled with purpose. She needs to be uprooted, gently or harshly, from her place so she can move forward, but she must have roots to begin with. (And if you must kill off her family, for heaven’s sake, let her be upset about it. That kind of loss is devastating.) It’s not quite as easy, but it’s a lot more interesting.
The Genre Salmon 
Yes, but – not everybody wants or needs ties. Think of that song about the Wandering Star – “Do you know where Hell is? Hell is in ‘Hello.’ Heaven is ‘Goodbye forever; it’s time for me to go.'” At least hundreds, possibly many thousands of people every year just up sticks and walk out of their own lives, and I suppose fantasies about people without roots satisfy that craving. I suppose they would be better art if you fill in the background they’ve walked away from, but perhaps then they wouldn’t fulfill the fantasy so well….
The trouble with generalizations is that they’re always wrong somewhere – you’re absolutely right that some people really don’t want ties to others and will choose to sever those they have. What I was thinking about was those characters whose entire family get killed off as motivation – or are cruel and mean for no real reason – who then rush off to bond immediately with the Love Interest and Faithful Companions, usually ending up by referring to them as ‘family’ and so on. If a character is an isolated loner by preference, and remains so? Perfectly plausible. If someone is completely alone for contrived reasons but *does* immediately fall in love/Learn To Trust Again/Sacrifice Herself For The Greater Good when the plot calls for it, then…. no. That kind of radical personality shift needs careful groundwork, and lots of it.
I see this done in character biographies all the time, for role play. The parents always seem to have died in mysterious or unexplained circumstances, and often the child is wandering on its own for years. Not really sure why people tend to do this, but after a while, seeing it again and again, it becomes tiresome.
I loved the Hunger Games, I have a boy in a story who has no parents, or so he thinks at the start. I guess many new writers are told to make their protagonist hurt and hurt bad for the reader to keep reading and probably the first thing they think of is death to the parents. I like to mess around with real issues in human frailties like mental health, illness or some other reason other than death as to why the parents cannot be there for the child or hero. Great post kept me reading and now I know I am on the right track with my characters struggles.