Except "bad for your health" is an objective biological fact, whereas saying something sucks is entirely subjective, so that argument too is invalid from the outset. You think it sucks, vastly more people don't. You're welcome to your opinion, but that's all it is.
Except the detrimental impact of Roblox is objectively and widely documented in various links in this thread and elsewhere on the inter webs. Kids don’t think junk food sucks, I guess millions of parents trying to keep them healthy are just going by their “opinions” as well?
Right, and now you're pretending that you said it was bad, not that it sucked.
Of course it's bad: it's factually and objectively bad, there's plenty of investigative journalism that unequivocally demonstrates it's absolute garbage and enables the worst kind of crimes the US can imagine. But, and this is important: that has nothing to do with whether it sucks or not. In fact, it "doesn't suck" enough for millions upon millions of people to use it every single day. Roblox is terrible BECAUSE it doesn't suck: the whole reason it's so bad for humanity is PRECISELY BECAUSE it's awesome enough for a large enough demographic to keep using it, while being opaque enough to the demographic that should be correcting this behaviour to not get it so that Roblox can keep getting away with it.
The absolutely biggest problem with Roblox is literally that it doesn't suck. If only it did, kids would stop playing it!
Roblox has, objectively, a terrible effect on the world. This is demonstrably true. It's not an opinion. But saying it sucks is. Words matter.