Isn't the harshness you mention precisely why it's worth posting here?
On the other hand, I don’t think the condescension or arrogance that’s fairly common on this site improves it at all, no.
Many will improve, with guidance.
Those that don’t will blunder along, wondering why they can’t make it in the world.
They are not pointless, those posts tell, that a clear explanation is missing.
Most people simply do not read a lot and in detail. If they don't get it after some seconds looking at things, they will walk away. And look at the next thing.
Summarizing a big novel project in simple words surely is hard, but very important.
This ‘criticize people to death’ shit should embarrass everyone here. We can be better.