because they, and 99% of their punters, don't give a toss, most small venue nights are just for the social anyway - take Goodyears in Wolverhampton, playing the same records now as they were 8 years ago, still gets packed and it's not for the quality of the music - it's the only opportunity people get to see their old mates and listen to some memories. People worried about OVO wouldn't attend venues like that in the first place.
* sorry Paul, wrote that without reading you'd said exactly the same thing!