I can understand arguments for generics, but they're complaining about trying to warm a whole pizza with a toaster. You need to put individual slices in, it doesn't work like an oven. Cook it with an oven if you want, but don't try to make it out like the toaster is offensive and useless.
Yes, you might need to re-implement these patterns each time with separate types (slice up the pizza), but it's not really a lot of work for the extra speed and crunchy pizza it gives you.
I'm pretty tired of the frequency of these articles where someone takes a concept from a language, tries to force it into a different language with little care for its idioms and then complains that it doesn't work.
Maybe I like digging holes with a trowel, maybe I like the precision it gives me, maybe I've worked out a way to with a little extra effort accomplish the same work. If you work with a spade and a bucket all the time don't complain that you can't throw a trowel around like a spade.