I think we should take the Kevin Lygo comment with a pinch of salt. He is known for making those sort of quips without actually meaning them.
Well, indeed, and I remember in the Melvyn Bragg series to mark ITV's fiftieth birthday that someone from ITV said that they didn't have much comedy at the moment, but there was lots of comedy in their entertainment shows like I'm A Celebrity. And of course at the turn of the century Granada's comedy department, especially, were producing just as many comedy dramas as they were straight sitcoms - Cold Feet won dozens of prizes at the Comedy Awards (hence in 2001, Jonathan Ross was pointing out how many times Andy Harries' name was being mentioned in the acceptance speeches).
These things do come in cycles and it is a bit sad that there currently aren't any sitcoms on ITV, but I think comedy needs to be of a particular kind to succeed on ITV, it needs to be particularly brash. The example I always give of something that doesn't work on ITV is High Stakes, a hugely unsuccessful sitcom in 2001 where a second series was commissioned but never broadcast -
https://en.wikipedia.org/wiki/High_Stakes_(TV_series). It should never have been commissioned in the first place, a dull middle-class series about bank managers looked totally out of place on the modern day ITV. It's totally unsuitable for the audience. It's nice to have sitcoms but they can't be just any old sitcom.
Probably the best period for comedy on ITV in recent years was around 2003 when they had TV Burp, The Sketch Show, Baddiel and Skinner and Directors Commentary with Rob Brydon, a nice little set of shows, and all of them I think were well-suited to the channel and fitted well alongside the other programmes. You could argue it was a better comedy line-up than BBC1 at the time. That's the kind of thing that would work for ITV, something suitably brash and vulgar.