It seems easier to bash Google than it is to debug the actual problems. I work at Google; not on Gmail but on things that many of you use daily. I don't believe my colleagues are trying to build market share by annoying specific users and dropping their mail. There are a lot of factors that need to be considered besides DKIM and SPF. Google has heuristics which are probably well justified with data, and it works for the vast majority of people.
Here is a pretty good reference to help you start if you want to figure out why Gmail hates you: https://support.google.com/mail/answer/81126 Mike