Under plurality voting, third parties are objectively bad for the winning chances of whatever party they pull more voters from (and/or bad for whatever major party you personally would vote for, if you personally vote third party). That might be what some people meant by them being “bad”, even though they prefer one of those major parties to win (and cheer on anything that makes the other party less likely to win). Although it’s certainly possible that some people just think they are bad in general. People do have different opinions, after all.
I agree that both genocides are bad, but I disagree on a few points:
The genocide of Palestinians has been going on since long before October 7. Hamas didn’t initiate it, they just performed a relatively minor act of retaliation which Israel used as an excuse to escalate the genocide.
For those of us in the west, our own governments are supporting the latter genocide. So of course we’re more outraged about the blood that’s on our own hands (in some sense). I think that Russia should be stopped as well, but not sending weapons in support of a genocide seems like a pretty clear first step we should be taking.