Smoking causes cancer, but smoking these specific cigarettes won't. Do you see the problem with trying to describe such an absurd situation to somebody?
You're making a different point now though, you're saying that people will associate it with scams which will hurt adoption. You initially wrote that the UX would be so bad that you'd have to convince users to bear with it anyway.
I don't know how they implemented it on the client side, but it's possible they kept it light, as they've been doing since the beginning. We'll see soon enough.
In terms of reputation, this is a long-term battle. Signal used to be quite unreliable in a lot of aspects, and hurt adoption. Now it's much better, making the migration from other messengers way smoother. If they're able to implement safe, private and convenient payments, that's one feature other messengers won't have to lure users away from signal.
I think you're confusing UI and UX. Yes, the UI could be kept light but the user experience can still be confusing because a payments feature is… surprising. Why would a messaging app come with a payments feature if not to make money and exploit the user?
Not saying that this is happening here but this is what people think, i.e. the emotional experience.
> just click through the scam marketing, ICO offers and "airdrops"
That's what I meant by UX.
> user experience can still be confusing because a payments feature is… surprising
Everything new is "surprising", that's a low bar. Chat apps in China have had this feature for years now, and it's also a feature in WhatsApp, a direct Signal competitor.