Totally agree. Ulterior motive is obvious unless you are literally standing right next to girls in a social environment, but even then...

Maybe it's not obvious in the culture where a lot of this pickup 'material' originated, I couldn't say, but here in the UK it can be obvious and you just look like a pussy.

With my limited experience I've formed the opinion that indirect is pretty much a waste of time both for me and the 'target'.

I think there are levels of being direct - i.e social direct vs sexual direct, statements of intent etc, but I think it's important fairly on to acknowledge that you are actively hitting on a girl (either by words, tone, body language, flirting-teasing, kino etc) in order to convey some sort of alpha-ness.

As I say, I'm not massively experienced in this, but personally I just feel like a beta-male if I don't do it.