First, the web 2.0 "craze" has already gone through its growing pains half a decade ago, we're in a different era now. Second, this is a false and misleading comparison.
What started the original "best viewed with" problems of the 90s? It was largely due to the lack of compliance with standardization. Every browser had its own buggy way to render content, often slightly different from the equally buggy ways that the competition rendered content. Most web devs at the time were undisciplined and lazy and they tended to use a standard reference browser as a guide for creating their layouts. This led to the insanity of sites that looked fine in one browser but were broken in others, typically due to accidentally making use of rendering bugs.
Now things are completely different. Standards compliant rendering is the norm for all of the most popular browsers. The issue today isn't basic compatibility as it was in the 90s it is now features. In order to push the state of the art in terms of new features on the web it will be necessary for some sites to remind their users that not every browser supports the features their site is built on.