I agree, to some extent, that distributions should move more toward "versionless" rolling releases, but the distributors will need to continue to test each update to make sure that it doesn't break things. That may be a bigger burden with a rolling release than a traditional stable release.
Distributions can't count on testing done exclusively by upstream developers. Interactions with the distribution's particular mix of other software and configuration options may reveal surprises that the upstream developers didn't anticipate.
Also, rolling releases won't help people running things like WordPress, which have lots of third-party add-ons. If you're running a web site that depends on one or more of these add-ons, you may find that a rolling release frequently breaks your site, because the latest WordPress is incompatible with the installed add-ons.
I really think that if projects like WordPress are serious about supporting production environments, they need to provide a "long term support" version similar to the Firefox Extended Support Release.