I prefer _schemes_ over _Common_Lisps_, and I prefer Racket of the Schemes. 

The author is just using the plural to acknowledge there are multiple variants of the scheme and common list languages and environments.

This is not uncommon.

> I just can't get past referring Scheme as "schemes".

That isn't something that happens in the article. Compare this sentence:

>> Now if you still want to use Scheme, Racket blows the other Schemes out of the water with what you get out of the box. […] But it is not without its problems.

> Am I getting punk'ed?

Only by yourself.