The VAST majority of people who posted that they don't tip are regional pilots. I'm sure they are those that do and that there are mainline pilots who don't. Ask the next van driver at a hotel that both regional and mainline use who generally tips the best.
I'm not sure how you can tell exactly where one works by their posting on this thread, but I don't doubt that if you spend enough time researching everyone who posts here you could likely figure it out. My time is a little too important for that.
Regardless, this topic was posted in the Regionals Forum, so I would logically expect the majority of posters to the topic to work for the regionals.
It was quite an entertaining story you related, however in the end your friend the van driver likely ended up costing her hotel some cash. Comair crews take cabs (agreed in contract with hotels to be paid for by the hotel) if hotel transportation has not arrived prior to 35 minutes after block-in.
When I used to fly freight, we never tipped the van drivers...but I'd always sit up front with them. I knew them all by name, and we'd visit with them as equals to and from the hotel. They would often give us priority over crews from a major airline I won't name (who tipped), I think because they appreciated the way we treated them.
Even in my first year I tipped the van driver...unless they provided sub par service. If I wait more than 5-10 minutes for a van and there's not a very good reason for it, there will not be a tip.
A tip is not given to reward poor service....anywhere.
I was travelling once in India. One night at a hotel one of our travel companion's rooms did not have any towels in the room. A call to the front desk was made for towels.
We had been specifically instructed not to tip the staff, as the tips were to be included on the final bill paid for by our host.
An employee of the hotel arrived at the room with towels that housekeeping neglected to leave in the room. After placing the towels in the appropriate location, he stood there waiting expectantly with his hand out. Our travel companions remembered their instructions, and did not tip.
The hotel employee picked up all the towels he'd brought and walked out of the room.
Our host was furious when he heard the story, and we were treated very well by the staff for the remainder of our stay after our host ripped the hotel manager a new one.