Eh, if they want to win the same way over and over let them. Once they face a real player with varied ideas and tactics they will be right back facedown in the ditch looking for another computer to beat.
Using the computer as a punching bag

Do you get money back from chess.com if your rating gets up to a certain point? If not, why are you worried about it?
What is the common sentiment among Chess.com members about beating the computer opponents time and time again to bolster up your points a bit? Once you recognize it's ever-occurring weaknesses, it becomes quite easy to beat it and you gain as much points as beating a human. Plus, it never learns so you can win with the same strategy all the time.
I just had a bad losing streak and whenever that happens to me I wonder whether it'd be "unethical" to exploit the computer in such a manner or if the majority thinks that a win is a win, no matter if it's man or machine.