When I read portfolios/personal sites like that, the first thought that always crosses my mind is, "They were looking for a creative way to say that they design _________ but settled on a tired cliche." However, that kind of marketing speak doesn't necessarily make me second guess the person's work. Rather (to use your example), some people may be great designers, despite the fact that they can't write their way out of wet paper bags (and thus need to settle on cliches).

Sizable personal bias aside, I have some data that argues you may be correct. When I rebuilt my website last summer, I built a fairly typical main page with lots of space for a headline. I spent the rest of the year A/B testing headlines to see which one got more people to delve deeper into my site.

I ran many tests, but the best performing headline I came up with was "Everything I put in this box makes me sound like a pretentious geek". The difference was truly immense - my pretentious geek headline outperformed everything else by at least 2.5%!

Consequently, my homepage contains the words "Everything I put in this box makes me sound like a pretentious geek". I sacrificed branding in favour of results...and I'm pretty sure my University would like me to give back my marketing degree! ;-)