Well I must be lucky.
I've flown a fair bit more than the average Joe and can -- hand-on-heart -- honestly say I've never had a real problem with check-in staff.
The've ranged from exceptional at the top (IE those giving me upgrades when I was travelling on my own dosh!) to the polite but not hugely efficient.
Maybe I'm easy to please but having worked as a bank cashier over 30 years ago anyone who can smile and be polite to the great unwashed has my respect!
PS I resigned from the bank after less than a year after I cracked and called a rude old hag , 'A fecking old gyppo'.....