I've seen a few comments from 'initially he was a very good leader' followed by some criticism. I didnt know the answer so google wiki and while a lite verison of events it might help people understand things better:
https://en.wikipedia.org/wiki/Robert_Mugabe#Prime_Minister_o...
Largely to me it seems he started with genuinely 'good intentions' that didn't work out, vs being a 'good leader'. Good to me includes both vision and execution.