That is your opinion.
Wandering around a wood having a nice morning out, maybe spotting a deer and killing it, if in season and safe to do so isnt doing the landowner any kind of service whatsoever.
You pass very little to nothing by using thermal for spotting.
The sole purpose of attaining deer stalking is to kill deer, reduce numbers or manage them on an acceptable level.
Thermal is, as I said, a valuable tool, which enables the user to be more selective when choosing which animals to kill.
You wish to do things traditionally, thats fine, take out a pair of jena bios, with a parker hale 270 and 6x42 scope and fill your boots.
Oh, hang on, werent the same discussions taking place in the 50's when chaps using open sights, saw an influx of "telescopes" on rifles, that made the game "unfair", the same argument over fixed power scopes vs variable , the same argument over the need for training and practice.
This is the same argument / discussion.
Times move on, deer numbers are at the highest ever, use the tools available to manage deer effectively.