That's the general idea of a lot of these MT systems. It's never the intention for the free to play player to acquire everything.
With that said, it feels quite cheap how expensive they are in a premium game. Uncharted 4 for instance, would take a similar amount of time if you wanted to unlock everything, however within that time you would have unlocked hundreds of outfits, taunts, weapons, and other items.
In For Honor, you could spend the same amount of time, and only obtain some rather crappy special effects, a handful of taunts and executions, and one or two additional costumes that are mere variants of the default.
I don't see an issue packing a game with enough content that the regular player will never unlock everything. In Uncharted, Overwatch, or Garden Warfare 2 the player will never unlock everything, but they will unlock a lot of content for their efforts, either way.
In For Honor, the player will neither unlock everything, or unlock a lot of content. It's a lot of work for very little reward.
Making matters worse, if we compare costume prices in For Honor, it's close to £15 for a single costume, which isn't even a complete freshly modelled outfit, but a variant of an existing outfit. Fighting games (e.g. SFV, DoA), offer new costumes, with new modelling work for £3, games like Uncharted offer new costumes, with new modelling work for around, £3, games like Smite and Battleborn offer new costumes for between £2 and £8. All of these costumes entail more work than the purchasable featured in For Honor, and they are all a fraction of the price.
You're right, but that also assumes that this game would be completely anemic on content if you took away the microtransactions (like a F2P mobile title is). Comparing this to a mobile title is a terrible analogy, since this is still an actual game.
Me personally, I think the game is fantastic, and has enough content to justify the price even without the cosmetics. Other people can disagree, but I don't personally buy the idea that a game has to be either free/cheap with micro-transactions, or full price and no micro-transactions.
I feel as though you don't play many mobile titles. I wouldn't describe games like Hearthstone or Clash Royale as devoid of content, even without the MT systems. Many mobile titles, and many free to play titles offer a decent amount of content for the free to play player. Most of the good mobile titles are still 'actual games' without their MT.