I don't know what the technical hurdles would be but I do think it would be a good option as an alternative. The Simple Menu is one of the best alternative menus in the KDE Store so I think it would be beneficial to have it included as an option in Kubuntu.
I don't really like Kickoff as the main menu but I guess that's another topic for another thread. :D
For now that is in our kubuntu-desktop -settings package. If we start shipping more things like that, might be worth splitting off to a kubuntu-plasma-addons package or something like that