If I'm being honest sometimes Ti feels like it just tries to strip humanity of well...it's humanity. Let me examine and break down this system as a set of rules and principles, facts, logical consistencies. Sure, with systems that's fine. Looking, examining, breaking down people in a set of rules, facts, and logical consistencies feels like someone is putting you through a fucking logical grinder and trying to strip you of your damn soul.
"Your are middle age, have low IQ, low stamina, insufficient EQ, and a poor cardio vascular system, these statistics determine you will have a low quality of life, less likely to procreate, and more prone to depression and suicide. Beep boop beep."
There goes your hopes, dreams and desires down the drain. You're no longer a human anymore, just a statistical outcome. Have a nice life with that information.
Followed by "What? it's the truth? People are so sensitive." dems fightin words.
But that's why Ti needs and has Fe with it. Fe helps curbs one's words and coats them in a nicer way. Too much Ti and the person loses any idea that these facts also can potentially cause pain to people, the Fe user helps deliver those facts less painfully, allowing for more wide spread and acceptance of the Ti information. As much as we like to hate on it, sugar coating has it's use on occasion.
And I imagine Ti's issues with Fi is that Fi is very partial to things and is attached to ideas and information that ti sees as either logically inconsistent, irelevant, or just flat out makes no sense. So an arguement goes: "I like/believe in this thing!" "So what if you like/believe in it! It doesn't make sense." Ti wants Fi to get it's emotional sticky fingers off everything and just look at the logical content without bias. They might think "Just because you feel strongly about something does not make it a fact."