Kids...levels of responsibilities....what they deserve (and when)...a lot of that stuff depends on the specific kid.
Making sure that they earn things that they are given is a solid general approach, but there are also degrees of various exceptions with things like Christmas presents, birthday presents, etc., where "earning" the thing in question is only part of the equation.
If a kid habitually loses or abuses things of value, then there's good reason to be hesitant about giving them gifts of much value (especially small and valuable things that are easily lost or broken). But if a kids has started to show that he or she has a good developing sense of responsibility, there's probably no real reason to withhold an occasional gift or reward of value.
I recently gave my daughter her first nice flashlight as a birthday present (she just turned 10), and although she didn't specifically work for it by doing chores or the like that specifically applied to the gift, she's been showing me a pretty high level of self-responsibility for things either given to her or left in her care. The flashlight is a further test of her sense of responsibility, but one that I think was deserved and that I was certainly willing to take a chance in giving her as a birthday present. She practically treats it like gold, recently even declining to take it to a sleepover with her friends for not wanting to take the chance with it (I suggested she take it, she said she didn't want to because she thought something might happen to it).
I definitely don't believe in showering kids with undeserved gifts, but if they've got an interest in something like a good flashlight, I'd rather give them something like a flashlight that has some real value and usability than give a $30-$40 toy or game that might either be outgrown or otherwise become an item of little interest in a short time.
I dunno...there are a lot of different takes on such things, but that's just my two cents on it (at least, at the moment). :)