Well, I for one got a Sony A7C and two Sony zooms (28-60mm and 20-70mm f/4 G), as well as two Chinese primes. And the awesome TTArtisan adapter that adds AF to old film-era glass. Had Sony closed their mount, I wouldn’t have bought a single thing from them.
This is the key part of their strategy: get the people who buy more than one lens (i.e. enthusiasts and pros) on board, and leave the low end of the market to Canon and OM System. Sony might be #2 in sales, but they outperform Canon in terms of income per unit, indicating that they sell more expensive cameras on average.
I think it’s funny that some people speak of Sony’s decision to open E-mount as some sort of desperate move. Sony love proprietary solutions more than almost any other global company besides Apple, and have become infamous for that. But back in the day they looked at the #1 seller in photography, and noticed that they had the strongest 3rd party support of anyone in the business, thanks to a “live and let live” approach. That company was Canon, of course, in the EF days. That’s why they also dropped the silly Minolta flash shoe, and embraced USB charging in camera before anyone else. Sony, as an outsider company, could see some things that the established players couldn’t, and one of those was how important third party products are for a photo system.