you look like you have a business plan in you, or don't really understand.
The QA cycle is longer than the kernel release cycle. QAing a kernel requires a set amount of time, at least for people to be happy that it isn't considerably worse than the previous one. Some of the benchmarks that enterprise customers care about can nearly take longer than the test cycle to get scheduled, they require hw that isn't always available. Never mind tracking down regressions using a bisect on a test that takes a week to run and process the results of.