Warning, long rant ahead.
I see a lot of people argue against the feh pass and how it isn't fair to f2p players. However, this is a game that you can 100% play for free.
And, what's more, there are no ads whatsoever. Zero, zip, nada. What other truly free to play game doesn't have ads? So yes, while the feh pass may seem annoying and in your face, you definitely do not need it to succeed. Would it make life easier? Yes most likely. But no one is forced to pay this monthly fee, and the monthly fee adds revenue to the game without spamming ads.
So yes, the developers can justify the feh pass as one, a way to generate constant revenue without relying on spamming ads, and two, upgrades of a sort to those who are willing to pay extra.
However, the game has become much more generous to f2p players with the free summon, summon tickets, free cyl (brave) unit, the spark, and even free units (such as Yen'fay) who ultimately blows most other 3-4 star units out of the water.
So if you allocate your resources you can definitely succeed in the game without paying for the feh pass. And no, Intelligent Systems is not greedy for implementing the feh pass.
Rant over
Tldr; the feh pass is not necessary to succeed in this game, and I would rather the feh pass exist than have this game full of spammy ads that you have to wait for 30 seconds before you can close them.
