Let's take a walk down development lane.

In the beginning, there was Auto-Attack and Tactical Points.
Auto-Attacks generated TP, TP is spent on special attacks.

Kind of like a mini-Limit Break.

Then some developer said "Auto-Attacks are boring, we want more visceral gameplay, let's replace the passive element with an active element" Good idea!

So they removed Auto-Attack and put in a choice of 3 attacks that generate TP.

Version 1.0 of FFXIV is released.

Immediately, we find that the system doesnt work well. It basically became a Manual "Auto-Attack" which is worse than boring. It's actively annoying.

The "TP generating" attacks were removed and Auto-Attack returned.

TP was still "Tactical" at this point since they were generated slowly over time. For those of you that need a WoW related point of reference, its a bit like Warriors "Rage" resource.

This is still quite annoying.

So the Tactical Points were changed again, to be modeled not on Rage but rather on Stamina. A resource that generates over time and starts at 100% (I dont think the original TP did that, but I could be wrong.)

This ended up completely seperating Auto-Attacks and TP, which originally were completely interconnected.

So think of TP as "Stamina" and it all makes a bit more sense, a limiting factor to Pace the player and prevent them from spamming certain skills. (Marauder Overpower for example)


Side note: The Warrior Wrath system is actually exactly the way the original system in 1.0 was designed!
Regular attacks (Butcher's block combo, maim combo, etc) generate the resource (wrath), once you have enough resource (Infuriate), you can choose to do a special attack (Inner beast, Steel Cyclone, etc etc).