Flights I had on Ryanair are merely 1 or max 2 hours long, (not taking the driving up and down the runways in account) and for this period of time some discomfort is perfectly fine.
Recently my flight to EDI didn't leave until it was due to arrive, an hour waiting at the gate itself with no staff to update on anything (the price you pay for barebones staff on no-frills
They get charged for using the gate, once they are on the tarmac "waiting for a window" they don't suffer additional costs.
It's not that they decide to "park the plane on the tarmac" it's that the interaction of various airport operational procedures make this the chepest option in certain scenarios, which is what they'll choose every time. Passengers bedamned.
In fairness though, I think though they've decided not to pursue this particular type of "cost saving" more recently.
Nonsense, the crew has limited flying hours, and sitting there will burn them up. I can assure you they don't want to have to cancel or delay a flight because the crew can't fly anymore.
* Moscow 2013 to Heathrow -- 4 more hours in the lounge, got €600 compensation.
* Heathrow 2014 to Bangkok, 5 more hours in the lounge -- got €600 compensation.
* Toronto 2017 -- delayed Delta flight to New York to catch a Virgin flight to Manchester so was downgraded and rerouted on KLM. No compensation as it was a U.S. airline. Lesson learned. (No lounge access either so cost me several beers)
I wasn't flying during the Volcano incident.
I do remember being delayed overnight with ryanair due to weather, but that was c. 2003. They wouldn't reroute me on the next morning flight to Anconna (rather than my original Forli flight -- only 50 miles away), so I had to buy a new ticket. It's attitudes like that which is the reason EU261 came in.