I would agree that it's useful if this wasn't 1000's of extensions added but that's not the case. The fact is web is not restarted and humans are creatures of habit. The sheer number of TLDs is going to contribute to user confusion. Was the site that guy told me .com or dot what? People in the USA tend to default to .com when remembering a name, or country.tld in other countries.
The potential for trademark abuse also goes up exponentially as well. Smaller companies with trademarked names will be at a disadvantage, as snapping up all TLDs of their trademark will get costly (good for the registrars, bad for the smaller companies).