I think the real alternative to the new web is the old anonymous usage, not at all single-sign-on. It would just increase the problems monolithic platforms pose.
With all due respect, TBL's W3C is also responsible for the last decade of monopolization. Not in the sense of acting in bad faith, but by keeping to fail on almost all accounts to bring forward the web, with catastrophic endeavors and priorities such as XHTML 2, WS-*, and the "semantic web". W3C had all the power and support they could wish for at some point, but they failed miserably to even keep browser tech in a sane state such that we'd be able to see new browsers being developed from scratch. Their current page for a HTML spec redirects to WHATWG's HEAD on github. In their name, newer specs for XML-centric tech such XSLT has been published by the sole commercial implementor of XSLT, violating their own guidelines of two independent implementations. The first thing they should do is reflecting on their abysmal track record; maybe they should make place for a true multi-national nonprofit standardization body rather than pushing forward as a pay-as-you-go organization.
Sounds like a bunch of quackery to me. Anyone who wants to build a browser today from spec can; it's just hard. I've written a CSS 2.1 renderer, so I have a glimpse of an understanding of what it takes.