It isn’t just how easy a tool is to use though.
It is about being confident about using it - knowing how to do things, what will happen next, how to get tone, content, style, etc right for the place.
Let me put it another way more familiar to me and not about technology.
I like shopping for wine. I can go into any one of a chain of wine shops (e.g. Majestic in the UK) and despite not knowing where any particular wine or region is, I know there is a tasting staton somewhere, that I can help myself to bottles and cases, that I am encouraged to buy 6 bottles, that staff will answer my questions, and that there is often a special ‘cellar’ area for better bottles. I don’t need to know any person there, nor where any specific bottle is, but I feel pretty much as confident in my usual shop as one in a town I’m visiting for the first time.
Now, if I go into an unfamiliar, independent wine shop, I have no idea whether I need to ask for someone to help me. I do not know how they range the wines, nor whether there is anything to taste. I might see a great wine, but not be sure whether the price is only if I buy a case, not a bottle. I might not be aware of the extra display space in the basement. I don’t know if the person at the till is just a shop assistant taking payments, or an expert who can help me choose a good bottle.
In both cases MY expertise is the same. In both cases I have the same motivation. But I am much more likely to interact with staff and other customers in the first instance than the second. I am also more likely to buy in the first instance. That is the point of “chains”
Therefore, if I am familiar with Discourse sites, I may quite happily leave a comment knowing that I will get an email notification of a follow-up, or that I can send a private message but only after I’ve been on the site for a certain amount of time.
That is why folks are more likely to leave comments in Facebook groups, or YouTube videos of complete strangers, because the process is familiar (Arguably that also has its drawbacks).
So, my point above was only that “getting to know the system so you are comfortable with it” is an EXTRA barrier to interaction. Increasing the complexity of the process in order to reduce possible social pressures may have no net effect on behaviour.
On the positive side, it is why I think Discourse is a good platform because it offers a reasonably consistent interface across different communities. While other platforms sell themselves on their customisability, it means they do not benefit from habits built elsewhere.
Apologies for long post - also trying to express something that was more of a reaction at first