My opinion: because there is a lot of money in education and it won't be possible to "disrupt" education and redirect this money if the current system is doing well. Notice how there is always a lot of money in being a disruptive company, at least for the top management (see Uber -- it is clear that it pays better to run Uber than it does to run a traditional Taxi service).
It also moves the goalposts. If everything is falling apart then it isn't such a crisis if the disrupted industry has teething issues once they strip cash out of it to pay for the heroes who are reinventing the system.
But if current educational systems are doing well, and slowly improving through incremental change, then it is a lot harder to argue that there is a crisis in education, isn't it?I think that the shilling is definitely half of it. Failures in the status quo can justify more money for something else. But the other half of it is a restlessness, a refusal to accept that there are limits to what education can do. We don't just want schools to produce some good results, we want them to fix all of the problems in the world. And they can't. No educational innovation will fix that, so eventually people ask educational institutions to shed the pretenses and openly become much more. Look at this post by Dean Dad, asking for community colleges to effectively become full-scale social welfare programs in order to plug achievement gaps. The moral case for providing for the poor is quite straightforward, but nobody asks the local free clinic to teach college composition.
Anyway, if this were only about marketing disruption, the teachers' unions would be saying very loudly that their results are more than good enough. Some do, but it's always tempered by lamentation over how much more needs to be done. And some of that is, of course, a call for more resources for themselves--failure can justify more resources for you as easily as it can justify more resources for your replacement. Some of it is also a heartfelt conviction that schools need to do more. The right and left both want the impossible from schools--the left wants to provide people with free schooling on how to catch a fish, the right wants to make sure that nobody can say "I was never taught how to catch a fish" as an excuse for not having anything to eat.