I don't usually see too many negative things said about them here. You'll always have people picking on bikes smaller than theirs, whether it's people with 1000cc bikes picking on 600s, people on 600s picking on 500s, or just about anyone making fun of 250s. You even have people on Honda's making fun of people with suzukis, people with suzukis making fun of yamahas, and people with yamaha's making fun of kawasaki, not to mention people with all 4 of them making fun of people with any kind of Buell. People with any kind of modifications that are anything but bolt on exhausts and other standard things will draw in some comments, which I'm sure you get plenty of with your tail.
In general I don't really think it's much to do with people not liking blasts, that's just kinda how some of the motorcycle community is. People on this site are definitely better than average but it'll happen anywhere.
You'll get some great comments when you buy a bigger buell or a ducati, but don't expect that to stop the heckling. You're gonna hear oil leak jokes about both of those brands until you die.
One of my first bikes was a ninja 250 and I loved it, so you won't hear any complaints about a blast from me. I still ride my wife's GS500 on occasion and it definitely has it's strong points, even if HP isn't one of them. To be fair that's not really a strong point of my xb9 either though.
