I don't think Carmelo bouncing around will have negative impact on he's remembered, but I think him bouncing around unsuccessfully will to a small extent, because it will just reinforce the negative aspects of Carmelo that his detractors had been saying for years: not a team player, selfish, can get you stats but not wins, etc.
Overall, I don't think it really matters, as I can think of a few guys who bounced around late in their careers with seemingly no negative impact on how they're remembered now: Iverson, Dominque, Hakeem, Ewing, Shaq, Pippen, Rodman, etc.