YABU. People want to put nice things on there. What would you rather see? I don't think anyone expects you to believe their life is perfect, just because they have chosen to share some of the good bits on FB.
^^This, surely?
I don't get all the FB angst on here. Surely most people use it to keep in touch with people that they don't see as often as they would like to, or as the modern equivalent of sending a postcard, or sharing something funny that they've seen, etc.
Yet on here, people seem to think it's all some kind of sinister cover up, or in your face 'showing off' designed to make others feel bad, eg someone posts a pic of some flowers their DH has bought, and instead of people thinking 'ooh that's nice', they say 'what's he feeling guilty about' or 'that's so unfair, I never get flowers' 
.
I use it for nice things like if one of the cats does something cute or funny, or if I have a nice treat out like a nice cake, or see a nice view, or memorably, to have a little chat with my elderly Luddite Dad while I was waiting at a foreign airport, that made his day because he is only just getting to grips with technology.
I might also have a little moan about the weather, or like when my bike got stolen - it's just posting random snippets of life - I think a lot of people on here are really reading too much into things TBH.