The theory behind taking out the thermostat completey, running the engine under normal operating and running conditions, is that it will distinguish the difference between a sticking thermostat as a problem, and a radiator being clogged.
I've had the misfortune of putting in a new thermostat when I was 16-17 and it stuck too. I was not a happy camper after needlessly flushing and replacing coolant in the radiator, just to find out I purchased a bad part, and have done the removal and run ever since. If it is needed for some kind of bypass, then this all becomes a moot point.
When you remove the thermostat, all that happens in most vehicles is that it runs cool rather than the engine coming up fully to normal temperature as there is nothing to stop and hold the coolant until that temp reaches the temp that matches the temp unique to the thermostat designated and designed by the manufactor. I have used two different temp thermostats in one vehicle at different times to run the engine at different temperatures. Another benefit of quick removal and test is, if you don't immediately have the part on hand, you can still troubleshoot the truck, and run without the thermostat until your part comes in.
All posts are good. There is more than one way to skin a cat and my method of madness is not necessarily the best way, just different. These guys know a whole lot more than I ever will, but I know what I would do in this circumstance.