> I'm just mostly in opposition of the concept that IMs turn conversations into addiction
Why are you so opposed to it?
Yes, IM does provide a lot of value and most people will not become addicted. Yes, other smartphone uses are certainly more problematic for most people. But searching for "SMS addiction" yields quite a bunch of hits, with a lot of them from before the smartphone era. This indicates it to be indeed a problem for some people.
Each case in the self help group for excessive screen based media consumption I visit seemed to have its own unique flavor. Don't think there was anyone with a heavy and exclusive focus on IM among them, yet. Probably cause the audience of this particular program is mostly male. There probably also aren't that much such cases in general. But I can totally see this being the addictive "substance" for some. And heavy users should watch out for detrimental effects on other parts of their life.