This hits the nail on the head for me.
Sometimes I don't mind if someone else makes the first move yet at the same time if they come on too strongly it makes me feel awkward and out of place.
I don't like it when a big deal is made, or when it feels forced.
Not to mention the stronger they come on the harder it is to reject them, and the less likely it is to get back to a normal relationship. I mean, even if I'm interested I don't want that much pressure.
I also feel like a lot of guys who come on really strongly have big egos, and then I of course feel the need to show that I'm not impressed and put them in their place.