There's not necessarily anything wrong with catering to "whale players", I personally am a F2P and I'm happy when I see new ninjas because it just shows how the game gives us more directions to go. Just cause a "whale player" has 20 super op ninjas, he can only use 3 of them at a time the other 17 can't be used at the same time and just set out on the bench. There is no reason for spenders to get more than that honestly other than for the collection factor (I do realize they can switch ninjas for various things so just want to acknowledge that but in PvP, most players keep the same lineup). Even if you talk about the meta, the meta is constantly shifting, so what are you going to do? Keep buying ninjas as they come out? If that's the way that you want to play it then be my guest, but there is no need to keep on changing your ninjas. While they may lose some value, at the end of the day, most top tier ninjas are equal and all balance out each other. For example, when Shisui came out, he was super popular and while his value has indeed decreased, it certainly is still very powerful and can compete at the top levels. Even more so for lower powered players, where the effects of the meta are much less prominent. As a result, releasing ninjas at a fast rate may cause the meta to shift and spenders who are able to get them, will buy them, the effects of this are generally very limited and often have more benefits towards the community rather than harm.

Anyways with all being said, I hope no one takes this the wrong way, I don't mean to insult anyone's opinion and I do enjoy hearing re*als for everyone else as there are fair points out there on both sides.