No. It doesn't make business sense from an opportunity cost perspective.
Diablo will likely require many more resources just due to servers.Ducktales came out in 1989 and that's coming to consoles this summer!
HOWEVER, for a series like this I doubt opportunity cost will be a big deal. They did those GBA ports of SNES games, but more importantly the games ARE massively popular and reliably sold for years. It's not unreasonable that even fairly straight ports can bring in quite a bit of cash, even if Diablo III's probably a better priority for now.