Why do people make "convince me not to get this thing" posts?

Like they'll post they're gonna get this car or phone or something and then they'll say "convince me I shouldn't get this."

Like why do you want people to convince you you shouldn't get it? If you like it, then go for it cos everyone's gonna have a reason why you shouldn't buy something.

If you listen to what they say on every car, or phone etc you may as well not have one, cos everyone's got something bad to say about it. Then you'll move onto the next thing and be like "change my mind" and they'll say some things bad about it too then rinse and repeat.