They constantly whine that it doesn't reflect reality, but that's because they're expecting more accuracy out of such a system than it could reasonably provide. It's inherent in the Te mindset that anything is worthless without x degree of empirical accuracy (decided arbitrarily by the Te user), so they don't buy the whole "it's constantly shifting to better reflect reality" thing.
They want a precise, consistent, empirical measurement that can be tested and proven objectively, and they consider anything that can't live up to this standard to be essentially worthless. They hold MBTI/other typology systems to this standard despite the fact that such systems don't purport to meet it.
So why don't you explain, firsthand from a Te perspective, what is wrong with MBTI and similar typology systems?