You can go too far with A/B tests, and maybe the Google execs realised that. You just end up with a fragment of your user base who like everything and convert well, and likely a majority who don't (to varying degrees, of course.)

To make a 'good' product, you've got to make some tough design and feature choices on your users' behalf. Case in point: Microsoft vs. Apple. Microsoft are well known to test extensively with "real" users, and Apple, well…don't!