Sure, what I'm suggesting though is making decisions that both satisfy however someone may think of his or her character and the drive for more XP. It's possible. Easy even.
To be clear, I don't dismiss your opinion. I address the objections you're posting to try to justify your opinion. "I just don't like it" is something I can't argue. "I just don't like it because X, Y, and Z..." when X, Y and Z are, to me, objections that are easily resolved is something I can argue.
Your logic is Barry the Bard could say "let's go kill those guys right now because it will be fun" when the only reason for Barry to say that is because Barry's player wants more XP.
Lipstick, meet pig. In-world justification comes after decision. That's what I object to.
My logic would be that my character is concerned that if we don't take out those guys right now they may go get reinforcments. If my PC has no reason to believe that they will leave or get reinforcements before I can recover from the last fight(s) then I would take the time to recover. If my PC could do one encounter, recover completely, go on to the next fight there has to be some reason to not do that from the PCs perspective. Fortunately there are many ways of doing just that.
Horse first, then cart. In-world motivation first, then action.