Alot of customers will agree to anything just to get on your books i have been in game 36 years and never dropped customers over petty little things like if you dont have them done in rain then throw teddy out of cot n drop them, most of my customers dont care about what weather s like but you always get the odd few that dont like it and most of them are the good customers so wouldn't drop them for that wow
Good for you.
For me it's not toy-throwing it's running my business on my agreed terms. Politely, reasonably, fairly but firmly. I would rather weed out the types "that would agree to anything to get on your books" at the start rather than let uneducated and demanding customers onto my round.
By your accepting "you always get the odd few that don't like it" and describing "most of them" as "good customers" just shows that you and I have differing views of what constitutes a good customer.
Meanwhile in my world I turn up and expect to clean as agreed. At the end of the day I complete my scheduled work on my terms with no "skips" "gaps" or "not today thank you's".
I certainly don't expect you to change after 36 years, but I do hope that other window cleaners set out their stall early on in their careers more to their own benefit as they may have 36 years work ahead of them and will have to live with the consequences.