Someone posted a photo of a car that, frankly, sucked. It was absolutely atrocious. There simply wasn't a single about it that was good.
Now, some folks here see that as blood in the water. They can't control themselves. It's not outside the realm of possibility that they actually feel a degree of sexual gratification by tearing someone else apart.
That's not my opinion, by the way, it actually happens.
Now, my comment was along the lines of "Dude, nothing is working in this photo. It's a compositional nightmare, the white balance needs to be addressed, and the horizon is crooked."
The poster appreciated my comments and, as you might expect, completely ignored the pinheads who were saying "This sucks" and "Why did you even bother posting, this is horrible"...
Is this a teaching forum? I don't recall seeing that as the primary function when I signed up. Perhaps you could be kind enough to direct me to where that's stated...
Do you have to? Seriously, do you have to? Is the world going to stop spinning if you don't? Will the world of photography suffer irrepairable damage if you don't?
No, of course not.
Will you get a charge out of telling someone that it sucks? Well, then your comment is being made more for your benefit than anyone else's and, as such, needn't really be shared.
The bottom line is this: there are decent people here, who would truly like to help others progress and imprive in their photography. Then there are the ass-clowns who lack the facility to be helpful and, instead, would rather try to paint themself as some sort of "expert".
Thankfully, such people are both easy to spot and easy to laugh at...