I don't buy the stability argument. I've had fewer issues with core bits of Debian than core bits of SUSE or RHEL. Quite often "stability" means "accepting out-of-date software", which just dumps the issues onto the users.
The third-party certification's immediate impact for me is the availability of binary blobs. I'm not trying to resell, so I can see that difference. My experience is with HPC systems, not customer-service terminals and the like, so perhaps my view is a bit skewed.
So you're right, the one enterprise benefit is a "for me" thing. The stability issue, though, I don't see as a differentiator against large-scale community distributions.