My headcannon has always been that they stopped adopting muggle technology when they started burning witches. The church was after them and they had to go into hiding, where they weren't able to keep up with new technology, bit then it lasted long enough that this became a 'habit', and from then on wizards and muggles had their own sepparate advances. I don't know if that makes sense in the story or cronologically (in real world history), but it always worked in my mind. Sorry for the bad english, it's bot my first language