I believe that "time management" is a joint MPA/Client responsibility...
Here's a real world example of what can happen when things get screwed up.
Recently I was at MP X. I arrived at 8:30PM for my 8:45PM appt. I went into the room after 9:00PM and the MPA arrived AFTER 9:15 PM, according to the clock on the wall. I'm very conscious of time because I'm an old fart and take a while to finish.
My session was supposed to be 40 minutes but we went over time. Just after 10PM there was a knock on the door, and I was already getting dressed while the the MPA showered.
The MPA left to find out what was up, and came back with the good news/bad news.
It turned out the MPA had an appt AFTER me, who left in a hissy fit because he didn't want to wait. He asked for his door fee back.
The MP didn't want me to pay the extra door fee, but expected me to make up the MPA's losses. Normally I leave an extra $20, but this time left $50 because I know the girl and didn't want to raise a stink.
The situation didn't sit very well with me because I could have thrown a hissy fit TOO, for starting 30 minutes late... Also, when did it become 100% MY responsibility to watch the clock??
Anyway, this is what can happen when time isn't managed properly.