Check out Material Design by google - its been a lifesaver to me who is from a very technical background. Best part is with very little work you can really impress your bosses !
Material Design is just like Apple's guidelines. It's great for helping to create something that looks uniformly designed and not a hodge podge of UI gimmicks, helping design-ignorant coders create something that looks nice, and as you say it's easy to get management buy in, but is it actually good? Will following it actually reduce your count of UI mistakes? Personally I don't like it at all, and I've had many complaints, both functional and from personal preference, with Google's design changes over the last few years.
But I do not have the time to go back and do another degree on design. Try convincing people with money to shell out extra for someone with good design experience.
I guess once we have millions of customers we might have to think about it - but small companies without much resources its hard to justify spending a lot of resources on good design.