Yes, that's what we're doing at CloudFlare. However, the patches to do it in major web server platforms are best characterized as "experimental" -- which is spooky for organizations to deploy into production environments. (We plan on open sourcing any work we do to improve them.) But, given how hard it is for most web admins to even manage one certificate, configuring a server to correctly manage two is... daunting. As you suggest, this change is undoubtedly good for our business, but I think it's bad for the web.