The real reason the crystals are easy to remove:::

So you can plug the radio into a computer interface or buddy box and not power up the "RF deck" when you power up the stick position encoding section.

Powering the RF deck with the antenna collapsed (common with flight sim use) can burn out that section of the transmitter. The unloaded output section heats up and can burn out. Pulling the crystal cuts power to the affected section.

If you pulled the crystal ofrom the tX being used as slave onthe buddy box you have prevented the possibility of the trainee flipping the switch on and shooting down some other model.

There is a good reason to be able to easilly pull the original crystal out... and be able to reinsert that same original crystal.