For instance, take an artist like Kazimir Malevich, who was a good technical painter, but his 'known' work is anything but:
That's not 'bad' painting as such, but the technical skill involved in his best-known works is quite low. It doesn't matter - it's an aesthetic quality of his work. There is a difference between technical skill and aesthetic appropriation and only knowing both
really lets you criticise anything with any value.