I agree on some level with the down voted comment below. As Yet Untitled, for me, isn't a very funny show. It can be kind of interesting but not hat funny. Somewhat engaging, not that entertaining.

Other shows such as Mock The Week have writers and people are preparing their punchlines from the moment they're booked and it's heavily edited, so the laughs per minute are expected to be greater. It's not exactly one of my favourite shows, that's just how it is. As Yet Untitled is different in that everything isn't a punchline. However, during preinterviews the guests pitch stories they'd like to tell too so there are some similarities between the two.

I also believe Mock The Week is intended for a wider audience hence the rapid punchlines. AYU also gets, generally, less popular talent which turns some people off. Most people like a familiar face, hence why Miranda and Russel Howard are everywhere. Even if they do suck, they're familiar.