>not having preference between working on three parts of the system is not abnormal.

I suppose it depends on the team and industry. This would be unheard of behavior for games, for example. Why you taking a pay cut and likely working more hours to just say "I don't know, whatever works?". You'd ideally be working towards some sort of goal. Management, domain knowledge, just begin able to solve hard problems.

Welp, to each their own I suppose.

Yea a lot software developers I’ve worked with, across the full spectrum of skill levels, didn’t have a strong preference about what code they were writing. If there is a preference, it’s usually the parts they’ve already worked on, because they’re already ramped up. Strong desire to work on a specific piece of the code (or to not work on one) might even in some cases be a red flag.