I was going to say what Len said, but he said it better than I would have. In short: it's precisely the right thing to do given the facts on the ground.The whole problem of the past few months has been guest spending. How the heck will higher ticket prices remedy that?
As for why not discount food/merchandise: they have been discounting merchandise, pretty heavily, since at least February. Food hasn't been, but that's probably more because of the captive audience effect than anything---if you are in one of Disney's theme parks, non-Disney food is a good 30 minutes away, minimum. (Then again, Disneyland's food prices seem generally worse, and there you can just stroll outside the gates for Mickey D's.)
Admission hasn't been significantly discounted for many years now---even the buy 4 get 7 deal was only realistically $10 off per $200+ ticket, because of the MYW structure. The theme parks are the reason people come to central FL. Without them, Orlando is basically still a farming community built on swampland (i.e.: a bad farming community). You don't discount the raison d'etre. You discount the ancillary stuff instead, and you ride admission as far as you possibly can.