I've heard this a few times from friends over the years when they didn't want to see a guy again.
Don't want to sound naïve but it seems very meaningless in my eyes, it's a clumsy way of saying they don't fancy the person.
Ultimately, they want a man who treats them very well. I'm guessing the man agrees with everything they say, has no opinions, they find him boring/not fun enough.
I think it's just a nice way of saying very bland. Has anybody else ever said this about a man and what did you mean exactly?
Not sure if men say it about women as much as there's more expectation for men to be the alpha, dominating type.