Disney would be asking for a losing battle if they entered the thrill ride arms race. Cedar Point puts out something new every other year to escalate the race and win the battle of being the "_______-est" coaster in the world by breaking records. Tallest, steepest, fastest, longest, etc. The theming usually stinks and the ride happens way too fast to tell a "story'... but it packs a mean adrenaline punch and does it well.
Disney just can't compete with that. If Disney did build a thrill ride of that magnitude, it would get one-upped within a couple years and would quickly fall in the thrill category as the Cedar Points of the world continue to raise the bar of what "thrilling" is every year. Heck, with how long it takes Disney to put rides up these days, it may be outdated before it even has a full open.
If they want to do a couple thrill rides with great theming and longevity like EE (minus disco) or ToT then sure. However, if we're talking about entering into a "biggest, baddest" war with the big steel behemoths... no thanks. Unless you're willing to continuously try and reinvent what is "biggest, baddest" every year and pour funds into making it happen, best to stay on the sidelines.