Game development is a horrible business to be in right now. The cost and time of development has skyrocketed, and one bad game can completely bankrupt a studio. They are being smart to farm it out especially if they don't have the talent. EA is a horrible company to work for.(full disclosure: I interned for them out of college and ran away as fast as I could once the internship ended) However, they do know how to control budgets and deliver on time. Something very important when dealing with licensed IP games that need to capitalize on other concurrent media. They certainly could go with another company, but I imagine many of them either A: don't meet Disney's requirements to deem them capable/reliable or B: don't want to touch that with a ten foot pole for a variety of reasons.
The only area Disney could really be competitive in for video game development is telling new and unique stories. They can use their IP ala Kingdom Hearts, but that's also very risky. See: Epic Mickey.
I loved Kingdom Hearts and Epic Mickey - and my older son does too, and we were super bummed when they pulled the rug out from under Disney Infinity (I'm pretty sure we have 90-95% of the figures, and we got the updates as they came out). THAT had massive potential, but infighting between developers/departments put the kibosh on that whole thing (and royally upset a lot of devoted players). We really love the Lego crossover games, but look at what happened between Indy and Pirates - Indy got a two-game series, and Pirates got the cheapo treatment because attention shifted to the next Lego: Harry Potter game.
Look at the app Magic Kingdoms - people love it, even though it's super simple and *sort of* a different spin on the Infinity idea (it's limited to MK, but it's got characters from popular movies and it gets new characters regularly).
Disney Infinity tried to be too much all at once...Disney and players would have been better served if the different brands were kept separate (Disney, Star Wars, and Marvel), and let's face it: no one is going to fall into the "buy this character figure to get it into your game" trap from Disney again and that idea is getting old anyway what with Skylanders, Amiibo, etc. Kingdom Hearts and Lego both rely on IPs owned by companies other than Disney. Magic Kingdoms relies on outside developers (which is fine only because they give it tons of attention), but as a game itself, it's very limited, and no one wants to continuously be forced into buying characters for such a limited game (in almost every new update, there is at least one character that has to be bought using gems, which in turn, are bought with money). Epic Mickey, while a fun game with beautiful graphics was only going to go so far simply because of the nature of the story.
I just think if Disney could learn from past mistakes and build a creative team that combines people with their ear to the ground in terms of gamers and what they want with people who have massive development talents - and combine that with people who know enough about the three big brands, that they could make a killing.
Maybe if they wait it out until development costs go down. I'm really NOT a fan of EA simply because their customer service is so awful (good luck getting any kind of response from them on anything).
