I'd just be a shitty game developer who isn't in touch with his own designs.
I'd sub shitty with inexperienced, but that more or less mirrors my own thoughts on the matter.
One of the things that's really interesting to me when it comes to games is actually the effect that small mechanics can have on one another when added up together.
I think maybe the problem stems from the fact that most anime games try for these really long progression cycles and it results in highly linear development paths that seem to offer a lot of customization options, but in reality the viable options are constrained by serious design flaws that ultimately result in almost every single person doing basically the same thing.
Even professional games suffer badly from this kind of ideology. World of Warcraft has always had a habit of only really having 2-3 viable builds per specialization because players are more or less channeled down specific play paths. A player's worth is their ability to put numbers on the screen and respond to specific phase requirements.
Then you look at games like Dark Souls, and every individual item can be the focus of a build. There are natural constraints for these builds that cause them to be more or less effective, but the element of surprise and practice is a big part of these games. Doing something entirely unexpected/suicidal can be highly effective because of how important mindgames are. It's not just about stacking strength or stacking vitality. It's about developing a synergistic strategy by either min-maxing a particular niche and forcing yourself into that position over and over again, or by creating a highly versatile, well-prepared build.
Because there's a lot of play/counter-play with items built into the game, there's a lot of room for interesting player customization without it having to be pre-planned by the developer.
This is called emergent gameplay and it's absolutely one of the most interesting aspects to me personally about game design.
What is the gameplay purpose behind locking players into focused builds, but asking them to customize their character "correctly"?