Those 1000 lines of what can be 10 in python are a good thing when the total code base is 10million lines and you need all those obscure corners. However many people hear that and decide that everything should be the 1000 line template/inheritance mess instead of 10 lines because their code base is multi-million lines line, when in reality most of your code will never need all the advantages the complex 1000 line solution gives.

There are places I have that 1000 line template mess that nobody can understand in less than a month of staring at it (including me and I wrote it!) because it is the right answer. Most of the time I don't write that because it is hard and there is no advantage, but once in a while it is the right answer to a complex problem. Those 1000 lines can turn many many 100 line problems into 5 line problems and so overall be a net reduction when done right.

The longer I write code the less use I have for inheritance. Templates are still useful.