You might say it's not sufficiently minimalistic, but the parent really isn't either and I'd say the lazy-loading implementation has to be a point in the favour of minimalism for NeoBundle
FYI, vim-plug also supports lazy-loading and the interface is pretty simple and concise [1].
NeoBundle obviously has more features, most notably supporting VCS' other than git, while vim-plug tries to be simpler and easier to setup and use (being a single file, no boilerplate code [2]). So they have different perspectives and I wouldn't argue that one is better than the other. It really depends on personal tastes.
https://github.com/Shougo/neobundle.vim
You might say it's not sufficiently minimalistic, but the parent really isn't either and I'd say the lazy-loading implementation has to be a point in the favour of minimalism for NeoBundle