If Steinar is responsible for removing query_cache in 8.0 I'm glad he's leaving the MySQL team. Sure, MySQL is not the perfect database heck I'm willing to even say it's not good or efficient, but it is extremely well supported across toolchains and programming languages. It just works and it works pretty darn well for most applications. I've built several startups on top of it some even exited.
There's a huge difference between "you don't need the best infrastructure to build a successful company" and "I left because the place had a culture that refused to acknowledge major product shortcomings". They work in different domains.
