There are roughly 3 phases in your career. In the first, you don't know much and do things simply, naively. In the second, you know quite a lot, and like it or not you will be quite attached to your own expertise, it will be part of your identity. Your solutions tend to be complex, but you believe they must be that way, and you have evidence this is so. In the third phase, you begin to perceive systems as ephemeral results of some causal chain, and have a sense of how they became the way that they are. This depth of understanding allows you to embrace simplicity again, but this time you understand precisely the limits of that complexity.

I think a lot of professionals (not just programmers) get stuck in phase 2. This is where, in our field, most of the code comes from: capable, smart people writing new code furiously, and with the not incosequential fact that it provably works. Sure, it has bugs, but you can get to those eventually. It also happens to be the most "defensible" phase, where you get to speak down to others - you have concrete experience, real knowledge, so you are justified. I would guess this is also the bulk of working programmers.

So, the OP's solution could be coming from a phase 1 or phase 3 place. You are certainly coming from phase 2. I would encourage you to stretch a bit and consider when the OP's simple solution makes sense, and when it doesn't. I would hope you would do this in an interview as well, because you'll find phase 3 people saying all kinds of whacky things, which might not make sense to you unless you ask.

(A careful phase 3 will make sure to preface his simple solution with his limits, and to not do so is a little bit sloppy, but personally I don't think that's a deal-breaker.)