If someone leaves praise without expecting anything in return, I think you can generally assume it's genuine. If, on the other hand, they leave a link to their own place, ask you to follow them, or hope to get something else from you, then the praise might be genuine, but it won't feel genuine.

I think the problem is that some newbies don't understand the difference between asking for reads in an engagement group versus asking for reads out in the wild.

If you're asking for reads in an engagement group (on Facebook, Discord, or elsewhere), that's fine. It's like being in a support group. There's expected reciprocity there.

But that's very different from begging for reads in the comment section of a stranger who is not part of the engagement group. The latter is more like invading a stranger’s house party and starting to beg the guests there to leave the party and come visit your house instead. It comes across as needy at best and spammy at worst. So I'd advise against it :)