DAI was designed around multiplayer. The combat in SP is MP combat with a pause button and tacked on 'tactical' mode.
They totally changed the play style from the previous games from a fully controlled party based combat system to a single character controlled action game in order to accommodate multiplayer. Tell me again how multiplayer is not affecting the single player experience?
Microtransactions have everything to do with why EA wants to cram Multiplayer into everything. I'm not saying they shouldn't, don't mistake me, just stating a fact.
That said, this discussion is off topic, since ME combat is already suitable for multiplayer (talking about the first 2 games) so not much changes there.
I would argue the game mechanics were designed specifically around the use of the tactical mode, moreso than multiplayer. Although that is certainly a by-product of that and there is no way of really knowing.
Think of it this way; the use of the tactical camera benefits from a lot of the moves performed by all three classes, including the chain and grappling hook attacks, long-range and area-based effects, the walls created by mages, and so forth.
Multiplayer certainly benefits from this because a lot of these moves "combo" for extra damage. In the single-player game we get that "on the fly" tactics the same way; your mage throws down a firewall, warrior grapple chains an enemy through it, rogue grapple hooks into the enemy then goes into stealth, mage continues onslaught by controlling other enemies with a blizzard, so on and so on. The tactical view makes it easier to plan this on the fly, while the action view can do it in more or less real time if you set the AI behavior right.
You also have a dungeon crawl type of game for multiplayer vs. a largescale campaign mode. Two different things yes, but the fact of the matter is its still multiplayer.
As for microtransactions, until they become intrusive, I will continue to ignore them like a lot of other people. EA is putting them in because it helps them make money, we all know that. It is irrelevant to the fact until we see it becoming a nuisance outside of cosmetic or random loot changes.
You are right though, this is still off topic.