You will have many experiences like this, Ive been flying on and off for 30 years, PPL, Instructor, Examiner. Flying does not conform to normal rules of anythng else I have been associated with, there is a lot of wasted time and energy in this game. Probably better if you feel the way you do, to get attached to a group rather that a club which has less strict time slots- you could have deiced the plane, had a cup of tea, warmed up then gone flying.
Sounds to me like bad management of the club. Most of the clubs schools Ive worked at required the instructors to have aircraft prepared and ready to go for first slot of the day.
If you want to arrive fly and then go home without any hassle, this game is probably not for you.
I get caught out sometimes usually when people who fly, never refill the aircraft with fuel on landing. This would save loads of time in a school.
I have had days like yours all day from start to finish. I shouldnt worry too much.
If you want 1 hours flying I would set aside 4 hours. Unless you own the aircraft. Even then can be time consuming.