Can new accounts be created from the platforms of the tribes? I thought that by doing so, you were directed to steem.

Yes ... but we can see who is the creator of the account, some of the main tribe accounts to create an account for their users .... the same that are doing steemmonsters, steemhunt, actifit

I wonder what would be the purpose of creating an account and then not use it at all? That is, not even a publication, this makes no sense to me.
Who would be behind all this?

Steem created the most accounts with 72,7% share.