My biggest beef with manual QA is that at most places I've worked for or worked with as a consultant (~15 companies), the QA team either doesn't have the skills necessary or doesn't care enough to understand the system at the level I would want if the company is going to spend money on manual testing. Most of the manual QA people I've encountered are either doing repetitive checks that I would want automated, or they are checking features in a way that I would expect the product team to be doing.

I've started to understand why large companies that attract high-quality talent (i.e. Google) put new developers on QA... you need a developer's mindset, while not being involved in the day-to-day software development to do effective and creative manual testing.