I think most of those trolls bash bitcoin here for one for three reasons:
1. they want to buy as cheap as "early adopters" because world in which they have to pay the current price seems unfair to them, i.e. not grown up yet.
2. they have convinced themselves not to buy last year, and now they thoroughly regret that decision and try to justify it to themselves. Not many people can accept the fact that they were wrong.
3. they are on a payroll, working for some whale buyer, accompanying his buys with background noise to not move the price up too much.
Hard to imagine any other reasons
A paid shill comes to mind....I guess that could be #3.