Lou Reed was never shy about sharing his opinions about other musicians. Take a look at what he had to say about The Beatles, Bowie, Zappa, Alice Cooper, and other contemporaries.
"He's probably the single most untalented person I've heard in my life. He's two-bit, pretentious, academic, and he can't play his way out of anything. He can't play rock'n'roll, because he's a loser. And that's why he dresses up funny. He's not happy with himself and I think he's right."
"God, do you really want my opinion on THEM? They are the worst, most disgusting aspect of rock music."
Apparently, the page is from this book:
And here's Lou Reed giving Zappa high praise at his posthumous induction into the Rock and Roll Hall of Fame in 1995. It's nice to see that Reed was willing to change his mind: