Life applications in learning math will be more useful to the majority of students who will never, ever have to figure out how fast a bathtub with a hole will fill up or when two trains will pass the same point from different distances and at different rates of speed.
:)
Perhaps some people just don't have the intelligence to abstract. Others are not taught how to recognize the abstraction. Most will never use the math in real life. Perhaps they shouldn't be taught math at that level at all. Colleges are filled with people who absolutely have no business being there based on their lack of ability and intelligence. There are other worthy pursuits that do not require math beyond basic arithmetic and algebra.
No kidding.
You're right in that most people will never have to figure out things like this accurately in order to have a fulfilled life. It is important, though, to know that it can be done. It's even more important to know what can't be done. Learning what can be done is an important step to understanding what can't be done.
Just look at the positively foolish things that a very large number of people today actually believe: You can choose your gender. Conservatives that drive SUVs are overheating the planet, while Liberals who fly in personal jet airplanes aren't. Global warming causes both floods and droughts, both hurricanes and doldrums. Equity makes everyone equal. Flooding the country with empty ballots doesn't cause vote fraud. Communism spreads prosperity. Etc.
Learning some basic mathematics, biology, history, and life skills helps each individual separate the chaff from the wheat in all the fields you must run through in life. You don't always have to be able to do it all from rote memory, but it is quite important to know what can be done.