I think there were sound problems. Can't see any other reason unless Morrissey is trying to teach us not to expect an encore every time
It was odd, as from where I was the sound of both the band and Mozzer's voice was fantastic, with Morrissey hitting all the high notes on the opening songs with no problems at all. For some reason about halfway through the set (from 'On the Streets I Ran' on I think) he started complaining about the sound and dropping the end off lines. He also seemed incredibly nervous - when he said desperately "Someone say something encouraging quickly" after one song I thought he was about the leave the stage halfway through the set - and completely forgot to introduce the band. I don't think he didn't do an encore simply because the crowd weren;t asking for it - it was an enthuesiastic crowd with lots of cheering, only sullen Moz assumed we were cheering the songs, not him.
I can only think of 2 reasons for all the problems, and the lack of encore.
1 - Bad stage sound. It sounded great out front, but maybe from on-stage Morrissey couldn't hear his voice properly, or thought he was signing out of tune. I;ve heard a few hideous bootleg recordings where a similar problem has occured and Morrissey sings totally out of tune for a song or two before they correct the stage mix, but oddly he seemed bang in tune and on form tonight, despite his grumbling.
2 - Is he ill? Lord preserve he isn't coming down with the flu or somthing...
If it was just a bad sound-mix on stage it's a pity they couldn't sort it out enough that Morrissey could at least give an encore. Myself I'm going to enough gigs that it's not the end of the world for me, but having gigs ending with enormous boos echoing round the venues from dissapointed punters is hardly going to endear him to new fans.