Kantai Collection is NOT a Gacha game. Everything is randomized without any pity system, and the only things you can buy with real money won't help you "win" at the game unless you dedicate time to train your units yourself. There's no EXP boost either (Small bits if you use Katori and Kashima in PVP, up to 10 times a day, real grind here) and Permadeath of an unit is as punishing as ever. Plus you can't choose whenver you want to give a specific skin to a specific girl. And no other fancy "Hey, 10% more chances to build Musashi in LSC today" or similar.
Pity systems, exp boosts, and rate ups aren't what define a game as a gacha game - that would be like saying that Overlord isn't an isekai because its protagonist never gets hit by a truck. Any mechanic in a game where you spend a limited resource in order to obtain a randomized reward is a gacha mechanic. If engaging with a gacha mechanic is part of a game's core gameplay loop, with mechanically relevant (as opposed to purely cosmetic) rewards that cannot be obtained via non-randomized means, then that game is a gacha game.
Ship construction and event rewards in Kantai Collection are randomized, and as far as I know, there is no non-randomized way to obtain the vast majority of shipgirls. I know that the resources you use for construction and running events in KC can be obtained for free via grinding, which is definitely not the norm for a gacha game, but I had assumed that there was some way to obtain resources faster or run events more often by spending real money, encouraging players to pay up in order to "skip the grind" - after some quick research, it seems I might have been wrong about that. Still, it's undeniable that the core design of Kantai Collection revolves around enticing players to "roll" on ship construction and events as much as possible, with new batches of girls added to the game periodically in order to keep players hooked who might otherwise get everything they wanted and stop playing. Whether the goal is to tempt players into spending money or simply to monopolize as much of their time as possible via grinding, the backbone of KC's gameplay loop is still a textbook Skinner Box that uses "waifus" as bait in order to lure players into the box and keep them there. Saying that Kantai Collection is morally above any other gacha game that does the same thing is preposterous.
