I’m not sure. I think establishing a certain identity is important for a channel in terms of making you interested enough to look at what they might be showing in the first place, and in knowing whether it’s going to be for you or not. Personally I know that there are loads of channels in my package that I never even bother looking at.
Dave is a good example of a channel building a strong identity, I think (and no I’m not biased because of the name) - the rebrand and build-up of original content alongside all the panel-show repeats and old BBC shows have successfully established it as the place to go for a certain sort of programme.
It can work both ways, though - earlier versions of BBC Three branding were quite effective in keeping me away from most of the show’s output, which I wrote off as mostly quite shit teen-oriented stuff. Since it’s moved to online-only I’ve been exploring a lot more of its stuff through iPlayer.
I do wonder whether the days of individual BBC channels are numbered, though - when watching stuff through iPlayer the distinctions between shows from BBC One, BBC2, BBC III or BBC Four are negligible, and I wonder whether the individual channel identities often do more harm than good in terms of separating out the content.