Apparently it was considered unbalanced by the Devs and a bit of code was introduced to silence the minor races.

Hmmm... Didn`t realise you couldn`t talk to minor races. You should be able to do. A mistake in my book.

So what do they even do in the game anymore?  Are they just there to be conquered for now, or what?

And what's imbalanced about trading with minors? Shouldn't the minors be eager to sell/gift some the stuff we give them in order to maintain relations with their other nearby major neighbors?  I always assumed the techs I gave to a minor race would end up in enemy hands eventually.