I've seen a few Simple Pickup videos from a few years back. I don't have strong feelings one way or the other, but I do see how it could be a positive thing.

If trying a few "pickup" tricks is what it takes for a person to break out of their shell and gain some confidence, then that's what it takes, and I'm happy they found something which works. Doing pushups in public or something doesn't really hurt anybody.

If somebody watches those videos and gets the idea that they can pick up anybody they want with a few pickup lines and some aggressive behavior, regardless of context or social cues... well, they were going to do that anyway, because that's their personality. Their "targets" are humans, and are plenty intelligent enough to see when a person is being phony, so it's not like these people are dangerous in any way.

I'm sure there's plenty of bad pickup advice out there, but again, that problem sorts itself out: the stuff which doesn't work doesn't work. The people who are smart about it will figure that out and try something else, and the people who aren't simply won't get anywhere.

I won't comment on "niceguys", because the idea is silly, but "redpillers" are going to be bitter no matter what. TRP doesn't make people the way they are; it just gives them a place to call home. If it weren't there, they'd hang out somewhere else and stew.