The opposite of tactical is strategic. I think of the difference as small picture, big picture. Tactical is "Take that hill." Strategic is "take that country."
So, a tactical response is a small, or limited-scale response. That's where the terms "tactical response team" and "tactical operation" are rooted.
But someone noticed that certain types of equipment and clothing were common to tactical response units. Not surprising, really. Soldiers have some universal similarities in gear. As do doctors, golfers, and plumbers. Your job defines, to a large degree, the tools you need.
So these tactical ops guys all seem to have certain things in common. A fetish for black. Carbines with a forward grip. Fancy sights. In steps a marketing guy and decides that, by applying the label "tactical" to anything remotely reminiscent of these items, he can increase the appeal to a certain segment of the market. It works, so more marketing guys start doing it, and the range of items gets wider. Trust me, Hanes is working on a line of tactical briefs at this very moment!
And so, the term becomes meaningless. Really, I'm surprised how drawn to it people, particularly young men, seem to be. Because "tactical" means "little." It means "limited." And you would think that these are exactly the sorts of inadequacies that these guys would want to de-emphasize in themselves!