Helps them from shooting themselves in the foot. My Grandpa/parents/non-technical friends could care less about anything other than Facebook, email, and maybe some Quicken type software. To them, alerts and pop-ups are just annoying things that they just click on until they go away. For them, 'secure boot' shuts down one of the possible attack vectors for malware that prey on this mentality. I know secure boot isn't a good solution, but when a company can make a change to make 99% of their customer base "feel" more secure, and in turn drive more sales, they will do it every time. Sucks for people like us, but hackers (that care about boot loaders) only make up a very small portion of the market.