Donisia
Donsie
Well, it certainly made it very difficult for enough people in the USA to establish the Simplified Spelling Board.
Also, English isn't a particularly difficult language to learn--innumerable people who speak it as a second language can tell you that.
English is, however, a very difficult language to master--many native speakers still fail to grasp basic rules.
For example, a wall is hard, not a test. A test is difficult