I have .com's, .net's and .org's. I use different TLDs for sites I believe represent different kinds of content, purpose and community. Having everything as .com would seem incredibly unnuanced for me.
But outside of country TLDs I haven't really seen much adoption of .name, .biz, .mobi, etc.
At least keeping the set of TLDs small and restricted to standardized names, or countries that people using them will recognize, helps to keep the recognition problem manageable. But allowing anything and everything for a domain name removes all hope of recognizing one without context.
That would be a non-techie in the US. Outside the US, people have to deal with more TLDs, more people are multilingual and hence exposed to more information from more countries, in more languages.
If non-techies in the rest of the world have one common trait, it is that they recognize the www-prefix as "Internet", not the com-suffix.