Because the budget thing is only an issue after the fact. There was no way to predict, on any account, that it would do SO poorly overseas in certain markets. And if they somehow did see it would fall short of the others, they figured the difference was worth it for what they were trying to achieve and the product they wanted to make. What probably happened is that they foresaw $800-$900 million overseas which would have been great. I can't imagine anyone ever predicting a little over $500 million. That equates to not understanding the public and societal sentiment around the world. Likewise, it also doesn't mean they "woulda shoulda coulda" made a difference with adjustments here and there.
Is it a learning lesson? Maybe. The jury will be out for a while on that one. I will say that Disney has already and quickly backed off of certain things they were deep into just a year ago. I will give a prime example. A year ago, on Disney channel during June, pride month was very very heavily pushed and featured with interviews, featurettes, etc. Never bothered me, but I did notice that this year during the same month, there was hardly a mention of it at all. I mean-AT ALL. And they've opened up to celebrating groups they never celebrated before such as Jewish and disabled.