A lot of people obsess about this issue, forgetting that there are many grades of mineral glass and Seiko's current Hardlex is among the very best and most resilient available. While it's not indestructible, it is super-tough, and I can honestly say in all the years I've been beating the hell out of my Seiko 007, it's never yet picked up so much as a scratch.
Sapphire fanatics also overlook the part that the overall design of a watch plays. A Hardlex crystal recessed below the bezel is less exposed to scuffs and knocks than a flush or prominent sapphire crystal, for example.