Also, the number of airline pilots who instruct part-time is restricted more than ever by the 900 hours per year rule. Everyone works much harder than in the past so most companies run their pilots up close to the limit.
If we instruct for free, we understandably get slated by those who get paid for it and either way if the school is making money out of us, even if we don't, it still counts towards the 900.
I'd love to instruct more than I do (no more than about 50 hours a year, all at the going rate) but I'm either too knackered on my days off or hitting 900 hours and the day job has to come first as it pays the bills.