I've seen the tactic called 'Pain Removal' a few places over the last couple of years. It's nothing new to the F2P economy, depending on a given developer or publisher's ethos. Warframe, for example, has been doing Pain Removal since Day 1. The community has never really minded because WF is a game about grinding and acquiring more stuff than you'll ever possibly use. Compared to Path of Exile, where how powerful you are has a direct impact on how fast you can clear content, and is all about bragging rights and having the best build and so forth. So Pain Removal is patently unacceptable to GGG and Path of Exile players.....mostly.
What I've read about SoW so far is that to see the true end of the game, you have to defend a lot of fortresses. And each fortress can have up to 6 to 7 captains + overlord. So that's like.....40+ Legendary Orcs you would want to grind for so your fortresses are the best and most unassailable forts you can have, and make the final series of attacks easier to beat.
So accepting that these practices aren't going away and are part of the norm, the question to me is what can you live with. I can take a lot of "pain" in game before I'll decide to spend money. (I think I've spent maybe $100 in Warframe over like 4 years, just because Potatoes take a lot of grinding to get the stockpile you want but don't necessarily need.) Pain and pain removal aren't issues to me that much as long as you can still win via skill and the pain is pleasurable enough that it doesn't make me put the game down. People saying you "need" Legendary Orcs in all your forts and it's a grind to do and that's a deliberate attempt to push people into MTX loot crates probably has to do with the fact Orc levels are very broad in SoW vs. SoM. You'll have low level orcs that aren't up to the end game snuff and they'll need to be replaced with tougher, higher level orcs farmed from the current content, because the stuff thrown at you in the end game will be very high level and your low level schmuks you haven't worked on in a while will be very outclassed.
That feels like a self-inflicted grind yeah but I don't think it comes strictly from a scheme to get more MTX sales. I think it's more or less a natural consequence of making SoW more RPG like and the fact that Monolith doesn't do game endings well at all. Combining those two, you get a redundant end game grind that on the surface appears to be an attempt to increase MTX sales.
Put another way, if the loot crates had never been added, I'm guessing we'd still have the same end game we're hearing about now.
I also think developers often get the shaft because everyone assumes what their motives are. So far reading I've come to a) Monolith still doesn't know how to do end games in a satisfying, original way. They really just recycle all the activities you've been doing the whole time and add some cutscenes and a QTE fight. b) Knowing the weakness in their end game, they did pad it out. Because that's what you do when your game play loop is so loose and open.