Whilst I agree an opinion can't be wrong, it can be misguided. You can have an informed opinion, or alternatively, an uninformed opinion. Opinions can change, and this doesn't necessarily mean hypercriticality.
If you happen to be responding to the previous persons post, at least he is trying to explain his opinions with reasons, and even apologised for being harsh, although it didn't come across that way to me, it actually came across more educational than dismissive.
Green Dragon said, "THE FIGURE STILL LOOKS LIKE CRAP! lol", and people took offence, but neglected the "lol" that was posted directly afterwards. Selective, out of context quoting led to him having to defend his position, or in this case 'opinion', which as you say "doesn't make it a bad opinon or invalid".
So maybe you weren't responding to the previous post, in which case, this stream has been even more educational, at least to those that are open minded enough to absorb it's implications in the first place.
What we have are opposing opinions, leading to open discussion, hopefully arriving at some consensus. In between we get emotional responses which only serve to escalate the taking of sides and reinforcing the 'we're right you're wrong' or the apathetic 'who cares' scenario we have all come to enjoy.