Honesty, I don't really see that much brand bashing here and if anyone does, I invite you to let me know with the report button.
However, note that there's a difference between saying something like, "Sony Sucks!" to "I prefer the Z9 over the Sony A1 because I think it's more rugged". I think the a statement like the second one is often misconstrued as brand bashing when it's really not - it's simply an option.
I think some of the issue is that when someone expresses an option counter to someone else's, the reader may imply something that's really not there (in the case of the example above, they may feel like the poster is saying the a1 sucks because it's not as rugged as a Z9, even though that was never stated). Also, keep in mind there's no way to have a constructive discussion if preferences are treated like brand attacks.