Those NCC/NCAs are unenforceable in California (outside some very specific exclusions, like C-level/founders), and California thrives, arguably because of it! I don't want my employer to be able to bully me into a contract where I can't switch to whatever job I want (even for "max 2 years" and half my previous pay...). A blanket ban clearly works and removes some of the employee/employer power imbalance. Should be the end of discussion.