I think TP's are the real Fe-structure-destroyers. Neither Te or Fe by itself can know of the presence of Fi without some help of repressed Fi respectively hardwiring with Ti. Ni can understand the motives, but doesnt take any Fi into consideration because it cant fully comprehend it. Although Ni is good at faking true understanding of Fi, it just relates it to... relateable things.
Also, in my observations. Fi tends to only want to see positive Fe emotions. Negative Fe emotions reveals a repressed Ti, where only positive Fe emotions keeps the harmony at top because there is almost no thinking at all. The same way as Ti don't want to see a happy Te (for example an ENTJ that is happy that his plan worked out reveals that he had an emotional agenda behind it).
And well, yeah. Fe needs to see feelings in others. Without seeing feeling in others, the Fe-users feels dead within itself and no way to manuever around in the enviroment, nothing to improve or move forwards to. Thus, this makes the Ti the opposite.