We don't know all the logistics behind the situation. There could of been extenuating circumstances with crew rest, etc.
Not caring about your time, or not caring about the time of the passengers waiting for an on-time departure to BKK?
Even jokingly blaming the Pilots for the delay kind of deserves a rude response, they did their job the best they could I'm sure, and aren't responsible for everything. I would tell them (or whatever DL employee did it) good job for finding the mechanical issue and waiting to get it fixed. They just got finished flying you to your destination safely, no need to get snippy with them.
In the grand scheme of things, a mechanical delay causing you to miss your connecting flight and rebooked same day on a different carrier isn't the end of the world. You will most likely get a gesture of good will in the form of miles.