I'm 50/50 on views on time keeping. Yes, I get extremely angry sometimes when either let down or kept waiting. More so by a regular than a new experience.
However, it must be acknowledged that they must get no shows and late punters every single day. Imagine you set aside one hour for a 30 min booking, for freshening up before and after, then he no shows. That is a lot of missed bookings/money. Even if late by 15 mins, that could fuck up the bookings after.
In an ideal world, if the punter is late and it will affect the booking after, they decline the latecomer...but then one in the hand is worth two in the bush as they say.
Sorry for the OP, definitely not his fault. But I get it from the WG side too.