I think you have a certain narrative about how the world works that you'd like the facts to fit into, but the facts - at least in Silicon Valley - don't actually fit into them. I doubt I'll be able to change your mind, but for bystanders' benefit:
The reason that programmers don't dress to impress is that their work product - the value that they add to other people - has nothing to do with their appearance. A programmer is paid for the software she creates; the user of that software has no idea what the programmer who wrote it looks like, and they judge the quality of it by what it does. So programmers have developed other metrics that they use to form a status hierarchy, notably the quality and difficulty of programs that you've written, but also things that are somewhat fuzzier like the technologies and tools you use.
Contrast this with a lawyer or salesman, where your buying decisions are directly influenced by how they present themselves and you often cannot directly determine the quality of their product. People in these professions have a strong incentive to present themselves well because customers have no other information to base their purchasing decisions on.
Certainly in the one metric shared across all professions - money - engineers at top tech companies are not being taken advantage of by management, nor are they "cheap grunts". A senior Google engineer makes more than all than about 2 of the salaries listed on the first page of a GlassDoor CEO search [1].
[1] http://www.glassdoor.com/Salaries/ceo-salary-SRCH_KO0,3.htm