Part I
Yet again we are flagellated, excoriated, eviscerated, etc. about 'mathematics'.
Still, some crucial points are missing. Been there; done that; learned the lessons; and below are some crucial ones.
Yes, candidate understatement of the millennium is that people don't understand math! Yup, they don't! That is, except mathematicians, and they are a tiny fraction of the population.
I review some of the main directions and then give my view of the crucial points and direction.
Best Undergraduate Major
Yes, in many ways math is a terrific subject. I recommend it as in many ways (not all) as the best undergraduate major.
Why? First, because in all the rest of the academic subjects of physical science, economics, social science, engineering, computer science, and now even parts of biology and medical science, 'mathematization' of the field is widely regarded as the best academic 'research progress'. E.g., mathematical (theoretical) physics is the most prestigious part of physics, and the situation is similar in the other fields. Second, because in all those other fields, nearly all the people feel that they very much need to know more mathematics. And, any mathematician who reads their work will readily agree!
In particular, the level of math in academic computer science research made some progress with Knuth and since then has, in a word, sucked.
Outside of academics, the level of knowledge of math is so poor that at the right time and place knowing some relevant math, that might not be very advanced, can be one heck of an advantage.
For such an advantage, there is a general principal, a double edged sword: For some knowledge to be a big advantage, it is nearly necessary that very few other people understand it. So, if you really do have an idea that can put $1B in the bank, before the money is coming in at a rate that makes the $1B look likely, explaining the knowledge to anyone else will give only contempt, laughter, anger, or silence. Generally people will give respect for something they admire, say, making $1B, but some knowledge they don't understand (without something like money clearly attached) will mostly just make them angry. In particular, for such math knowledge, people in business won't understand the math, and people in math won't understand the business. It can be lonely at the top, or as a pioneer, etc. Generally, having a big advantage later can be valuable but at first can be lonely.
Getting Paid
Since for nearly everyone, most of their career has to be directed to getting paid, we need to say how math can contribute.
My guess is that for at least the rest of this century, math will be more important for computing than Moore's law is, will be, or, really, so far has been. So generally I'm optimistic. On this point, I expect that so far nearly no one will agree with me. Still, such importance can be a long way from getting paid.
Money for Academic Math
For the more technical academic fields, there has been one main source of money -- the US Federal Government. Why? Before 1940, f'get about it! After 1945, D. Eisenhower, J. Conant, V. Bush and others were so impressed by the role of math in WWII that Eisenhower supposedly said "Never again will US science be permitted to operate independent of the US military." Conant, et al., deliberately set up several sources of funding -- NSF, ONR, etc. -- so that there would be no one place to cut off the flow of money. The Cold War and the Space Race added more funding. By 1960, there was so much money for research, including math, that a joke went "While you are up, get me a grant.". Now commonly the top US research universities get about 60% of their budget from NSF, NIH, DoE, etc.
Scenario: You are a university dean of the School of Science with the math department, and they want to hire some profs. As the dean you look mostly at (1) prestige for the university, (2) demand for courses, and (3) opportunity for research grants. There (1) is okay for, maybe, 50 mathematicians today. For (2), mostly f'get about it: The other departments and the math profs agree that the math department shouldn't teach 'service' courses. So, the other departments want to teach the math themselves or just f'get about it. Besides now there is a history of math department service courses taught by people who didn't speak English, and bitterness remains. For (3), some years ago there was an Exxon executive David who lead the writing of a report that basically claimed that the research and teaching in the math departments was next to useless 'abstract nonsense'. One result was that the NSF, etc. felt more justified in cutting back grants for math. Math had too little support in Congress, and there were plenty of other fields that wanted the grants instead. Net, in the research universities, the math departments went on meager rations. They still are.
So in academic math, where is the 'action'? Well, there is plenty of screaming that K-12 needs math teachers. Okay, so there are colleges with math departments that specialize in such 'math teacher training'. Those colleges need some profs who got math Ph.D. degrees from, say, a state university. There the math profs got their Ph.D. degrees from research universities. And there the math profs do research on generalized abstract nonsense that may not go useless forever. So there is a pyramid with several levels, the lowest of which is K-12 math teaching and the top of which are the math departments at the usual suspects Stanford, Berkeley, Princeton, Harvard, etc. Of course what a Princeton math prof does is essentially irrelevant to anything in K-12 math. Being irrelevant is economically risky!
This pyramid is at risk: E.g., college departments of education might just do their own teaching of math to students headed for K-12 math.
So, here's the good news about academic math: The stuff on the library shelves isn't going anywhere!