I don't think that a potential number is indicative of your love for an operator though, that's more of a money\savings situation.
I have Arturia pot 3 because I had to use 300 rolls on her banner to spark W. I'll be content with pot 1 otherwise, doesn't mean I love her any less. I also have a pot 3 Viviana because of that, that doesn't make her my wife (she's all right though).
And no, I won't M3 skills that I'll never ever use under any circumstances. I have M9 Nearl, for example, because I actually use all of her three skills.