Don't think that engines and BM are mutually exclusive. A lot of boards have neither a strong engine (lack of trashing, big draw, +actions), nor a strong BM enabler. You shouldn't train yourself to either go for an engine or BM, but rather think about the strongest possible deck and which cards it should have. Try to picture the contents of your deck right before you end the game while ahead and start thinking about how to get there as fast as you can. Sometimes fast is horribly slow, BM is never super fast and often easily disrupted, but engines can also take a lot of time to come together.
People tend to overvalue engines because they're a lot more fun to play. Playing 3+ action cards each turn gives you a feeling you're really doing something, even if you can't afford an Estate. As a reaction to this, people like to punish these village idiots by playing simple BM.
Don't be part of either camp, be part of the pragmatic camp if you like winning. Still, getting a feel for how to build a good engine is a lot harder than figuring out how to.optimize BM. So there is a lot of value in going for the engine even if you lose. You'll probably learn more from it.
Experimentation is key and more rewarding in the end. I have so often felt so foolish taking a known default strategy and losing to a surprising out of the box engine. Not because I lost, but because I didn't have the guts to try it myself.