There's commiseration and affinity there, too. People who say they're bad at cooking will still cook. They're lowering expectations. Additionally, you can "check your math." If you say you're bad at math, run some numbers and then check it to find yourself wrong, you also found yourself right - and you can go back and fix it. Saying you're "bad at math" prepays for the time necessary to do it right. The main thing, though, is that nobody uses math. It's a safe thing to say you suck at. Once you're clear of college the only time most people whip out Excel is if they don't have a copy of TurboTax. I think the STEM crowd is uber-defensive about math because they're required to take so goddamn much of it and as soon as they're out in the real world, they rarely use it either.I don't think people say they're bad at math because it's a thing to boast about, it's just a belief that they could never be good at it.
Once pretty much any STEM professional is clear of college, and even in college when we're clear of our required math courses (including intro physics; intro physics is at its most fundamental a lot of empirically-validated math plus crashing shit into other shit or shining shit at other shit), we use computers to do our math. It's impossible to do ANOVAs by hand unless your data sets are, like, n=5 each, for example. Also physicists work with absurd numbers of significant figures. Knowing why you're using a given equation and when to use a given equation are the main things one takes away from the math we take. EDIT: And you most definitely use math, you just don't think about it. Tip calculation, building shit if you do DIY type things, calculating costs of things within a budget, etc. You probably don't use trigonometry, I guess, but I'll be damned if you don't at least do some algebra and geometry on a moderately frequent basis. EDIT 2: You actually might use some trigonometry, but I guess more in an intuitive sense. A lot of math actually gets used this way in practice as sort of a predictive tool. You have 4-function calculators; we have calculators with a bazillion functions. Nobody says they sucked in history or high school government or music like they were proud of it. When's the last time you had to whip out your knowledge of Greek civilization? Trivial Pursuit? And you can check your history by cracking open a book or Wikipedia. It doesn't help, either, that scientists got painted at one point by - somebody in the media, I guess - as social pariahs, the stereotypical 'geeks', or that one of the first Barbies was programmed to whine 'Math is hard'.The main thing, though, is that nobody uses math.
Computer's don't do math, they just do the computations.