Sure, but we should consider which outliers most internet discussions end up encouraging. They're going to encourage people with fewer family/community/social/hobby/work obligations, because the more of those obligations one has the less time one has for online discussions. It's going to encourage people who spend less time writing their comments, because if you're spending 15-45 minutes making sure your comment is of high enough quality you're simply not going to be able to make many comments. If you spend a few seconds/a few minutes writing one, you can make a lot. It's going to encourage comments when people are outside of their own areas of expertise or when they don't have much to say (because you're not going to be seeing all the people who refrained from commenting).
You mentioned voting, but the same issue applies. Someone who has fewer time obligations is going to end up upvoting/downvoting a lot more comments than someone with an very active offline life. Someone who votes before reading an entire comment is going to be able to make a lot more votes than someone who does. Someone who upvotes/downvotes everything because of how they feel is going to be giving out more votes than someone who wants to reserve those for truly bad/truly good comments. Someone who checks whether or not a comment is true is going to have less time to vote than someone who doesn't. Someone who has time to refresh a page every 10 minutes throughout the day is going to be voting earlier, affecting what comments/posts even get seen by less active user (people with other things to do miss a post because really active users downvoted it off the front page within 30 minutes).
A lot of people seem to be unaware that this is an issue, and think the internet is representative of society at large. But commenting and voting as much as you want encourages certain kinds of content from certain kinds of people (a small subsection of people[1]), and discourages content from others.
[1] https://en.wikipedia.org/wiki/1%25_rule_(Internet_culture)
> people with fewer family/community/social/hobby/work obligations, because the more of those obligations one has the less time one has for online discussions
seems like a bit of a category error. There are any number of stable online groups that should be considered under the rubric of "community/social" activities. People participating in them know and expect things of each other, just as they do in a face-to-face group.