ESL students find -ed words hard to recognize and even harder to pronounce, whether they are being used as part of a past tense verb or as an adjective. (Add an -ly to make the adjective into an adverb and pronunciation becomes a double challenge.)
Adding to the problem is the increasing dropping of the -ed by English-speakers themselves during adjective usage! I first saw a grocery aisle with the sign "Can Goods" 40, or maybe even 50 years ago. The English teacher in me said, "No! I must talk to the store manager about this!" Of course I didn't, and over the years supermarkets have almost universally adopted the shortened version.
Equally disturbing is the number of restaurant menus offering "ice tea" instead of "iced tea". A quick Google search found that Grubhub says, "Find your favorite ice tea delivery near you..." but Olive Garden still advertises "Fresh Brewed Iced Tea...". (I think they meant to say, "FreshLY Brewed Iced Tea..."}
Well, languages do change. In 100 more years there may be only a shorten' version of "well behav' dogs" or "promise' land" or "hard-boil' eggs". At least that will make the language easier for ESL students.