Hating on modules seems to be a common thing. Not just specific modules, but the abstract idea of them. I agree that many modules have problems. Many modules are so poorly laid out for actual use that it almost makes more sense to build something from scratch than to try using them at the table. Many classic AD&D modules fall into this category for me, with their huge wall-of-text room descriptions. However, even hard to use modules can also be read like literature and mined for ideas. Additionally, there is the benefit of getting out of your own head, at least to some degree:
Anybody can make maps and stock them with monsters and treasure. You can even do it randomly. Off-the-cuff refereeing is a skill that indeed requires no outside support, be it commercial or free. But I know when I buy an adventure, I am seeking in-depth descriptions that make the map and the contents of the location come alive, and hopefully in a way that I would never have done on my own. When I run someone else’s adventure, it’s because I want the challenge of running something different, to present my group with something different. Changed names to integrate a work into my setting aside, I don’t want to make an adventure “my own.” The whole point is to escape that for a bit and to charge my own creative batteries by basking in someone else’s creative light.(From the introduction to Hammers of the God)
I would add a few more practical considerations that favor modules. The first is that it’s almost always easier to learn from examples than it is to learn from manuals. Any programmer will vouch for that insight. The second is that modules provide communal shared experiences. The third is that time is limited. It’s not hard to bake bread, but I still often defer to the baker.