Your last essay was rather apt for where we're at right now (just getting into the fundraising waters), but terms like someone reputable are kind of hard to gauge -- especially in the somewhat inbred world of investment when you don't know who's buddies with whom and as such whose opinions are worthwhile. Here a lot of companies seem to be run by serial entrepreneurs, which often seem to be a little too buddied up with investors to side with first-timers when trying to shake out info about what dealing with them is like.
We just tell YC founders to ask us, and that probably is the most effective way to judge a VC: ask people who know him.
In most creative endeavors, quantity leads almost inevitably to quality.
If there is some change in technique, or some application of capital, that would let your company crank out LOTS of apps instead of a few mostly-pretty good apps, then the VC is absolutely right to suggest it. Write so many apps that you can throw away that bottom 50%, and not even notice.
John Lennon and Paul McCartney became expert songwriters by writing an incredible quantity of songs.
There are creative ways to leverage talent. What's stopping all those "mediocre" developers from building apps? I'd bet that at least 1 in 10 of them are better at it than you or they think, or at least, would be with a little practice. How do you take advantage of that?
It's up to you to know how to set up virtuous spirals, not the VC. If you can't do that, then why should they give you money?