Stuart Ellman: Not Everyone Gets a Trophy
businessinsider.com
businessinsider.com
The author seems to feel there is little upside to being straightforward with people and alot of potential downside. I think if you're truthful without being a jerk about it people will generally appreciate it. Those who don't are probably not the kind of people who whose opinions will greatly hurt your reputation anyways. Shouldn't better communication always lead to better chances of success?
There's a more nefarious reason for the so-called "political correctness", although this may not apply to the OP. VCs never want to say no; it's easier to be noncommittal.