That is because the average startup culture thinks everything other than web/mobile is not interesting. All the system architecture guides I see these days consist of load balancers, webservers and databases as if that is all that matters.
Biotech, medicine, electronics, wireless technology, signal processing, chemistry and material science startups work in different environment. Get good education (PhD is requirement in many areas), work in a firm or research group until you are at top of the game and have learned all practical skills, then start a business.