Are you stalking me, Caliban?
Because it is not normal practice, movement clapping tends to be done by only a relatively small minority of audience members. It therefore tends to sound weak and uncommitted. So what is intended as a show of enthusiasm usually comes across as an embarrassing aberration - hesitant and half-hearted.
Some people just cannot stand silence. At the Olympics they play loud background music when nothing else is happening, just as they do in 20-20 cricket. At the Proms, when the music stops for a momentary pause, some people feel they have to fill it up with noise. Mendelssohn tried to overcome this by linking his movements. Conductors do the same by rushing into the next movement, which is a pity, as it removes that precious moment of silence.
The worst inter-movement clapping I've heard this year, so far, was in the Smetana quartet arrangement. Perhaps they didn't realise that it STILL had four movements, or whatever.
Most conductors get very annoyed at noisy late-comers searching for their seats. I remember Beecham, turned round to face the audience and waiting a very long time for them to settle themselves, red in the face with embarrassment by then. And Sargent once stopped a piece of music when a flashbulb exploded or made a lot of noise, then started the movement again.
Both of them seemed to be able to control inter-movement clapping by keeping the baton aloft to signal 'more coming'.