I'm generally not a fan, either. But this one will be a nice convenience
for me because I have many Melda products and updates are frequent. Ideally, customers would be given a choice between all-at-once and individual installers, but nobody's ever gone to that trouble, AFAIK.
I'm just guessing here, but there may be another reason for implementing this installation method. I'm thinking that Vojtech may have pulled common code out of the plugins and moved it into a shared runtime library. This would substantially reduce each plugin's size, and would make it easier to implement his new chainer Mxxx (still in beta). Just a guess. At least, that's what I would have done.