For me it's mostly about amount spent vs. content received, spending $100 and pulling largely duplicates or units that are otherwise available from clearing missions is absolutely soul crushing because you aren't actually receiving anything new. Even if you're technically receiving -power- you're not receiving something that feels good to obtain, that coupled with the fact that someone could spend $10 and pull two Deines whereas I can spend $100 and not see any black let alone the two advertised with the supposed bonus pull rate (Which never matters if you can never pull a black to begin with) feels pretty discouraging.
I feel like giving people extra means by which to acquire crystals overtime doesn't necessarily make people more apt to spend, it might even make them less likely to because if you don't pull anything good with your free rolls you might just assume my mindset and say "Well, I didn't pull anything good with X amount of rolls so why would I bother again, let alone spend money". I basically threw $100 at what is likely going to be the best opportunity to get Deine and struck out, so why would I ever spend that much again? Even if I were to get her after spending again it wouldn't have anything to do with something I did "correctly", just the server calling my number.
Not meant to be complaining necessarily but just my mindset, the gacha is literally like playing the lottery. Some may win but for everyone else you're better off saving your money for more sure investments. I bought into the advertised bonus rate and got burned, that's all. I just won't touch the proverbial stove that is the premium gacha again (With money).
