If you can find the previous post, I believe blizzard has made is so you can't use trainers in single player mode now. They're having a lot of trouble making one and I think they've just stopped. ( Not 100% sure on this as I cant find the thread now. )
You can look at most of the Starcraft trainer pages to see that the series has been retired, the info is in the trainer thread. You are correct in you assessment of Blizard's negative changes. PWizard has stated to send your regards to them for lack of trainers for SP games. The trainers now result in instant bans with no fix in sight so the series has been permanently retired. You can see the permanent status on the requests page.
[Edited by Vlad_the_Bad, 10/11/2015 6:54:26 PM]