"Tactical" isn't really the best word for it (hence why I've never claimed it was more tactical), but I can see where some people are coming from when they say it's more tactical, and this partially involves what I said about what we expect from boosting. But, again, I am not claiming the delay is *more tactical*, just that I think understand where people are coming from where they say so.
Here is the definition of tactics Exeon linked to.
: of, relating to, or used for a specific plan that is created to achieve a particular goal in war, politics, etc.
With this in mind, again, some of see boosting have a function of aiding offense. But don't look at it from an offensive standpoint. What is to be considered as a whole when you decide to boost (As in getting from point A to point B)?
Potential for being seen on radar. Fuel usage. A half second raise delay that would make ambushes slightly harder to counter (let's say the ambush is by a single mech). The fact that you cannot shoot while boosting.
As one approaches an enemy, all this must be considered. Once you get to an enemy, though, that's where dodging, jumping, aiming, and heat management come into play. Among other things.
With the delay gone, there is less to consider with boosting. Radar and Fuel are the same. Ambushes are slightly less of a detriment because you can simply start shooting. The opponent has less of an advantage for getting the drop on you. And so, it goes from "if I get ambushed I'll be slightly vulnerable and I can only hope to counter them or run away" to "If I see an enemy I will shoot."
The shooting while boosting is still there, but with no delay you no longer heavily consider the pros and cons of stopping a boost to shoot.
And with less detriments you potentially have more reason to boost in more situations (not all, and not necessarily a major increase). And if you boost in more situations, you are actively not considering other means of getting to where you are going, and as such this can be seen as fewer tactics because, since the boost is "better" and more "favorable" you can afford to do that more, and other methods less.
But this is just a guess.