Love bombing is also a tactic used by narcissists. They bomb their intended victims to gain loyalty and exclusivity, then move on to more dangerous forms of treatment.
Much of the love bombing that church people do isn't intentional; it's broken people doing their best to be kind and friendly. Some of the cults do it intentionally, and some churches do it with good intent, but that doesn't make it a good practice.
As an introvert and observer type, I am less keen on being effusively welcomed if that's all there is. Friendliness with nothing behind it except, "Here's an offering envelope" isn't going to cut it. While I'm also the type to get involved in helping where I can, if I get the sense that someone just wants my practical involvement without being truly relational with me, I'll vote with my feet.