If everyone posted a repetitive and/or meaningless (even if individually innocuous) comment or image on every new user, the system would be destroyed not only by the clutter but by the sheer volume of comments.

That's not posible for humans to do as I already stated on my own introduceyourself

I said:

I am "human operated" and this means I will try to welcome new steemians but don't expect I will be able to reach every new #introduceyourself post out there."

In 1 week I could reach 89 people and it took me about 20 minutes for each "welcome action" because (once again) it's not about doing "the same" over and over again, each case was handled accordingly. Talking about a "repetitive image" is like saying using the "steemit" logo over and over and over again is like "spam". I just used a sign, but that doesn't convert me into spam or a bot, because each action was unique and handled according to what was needed.

If another person wants to copycat what I did, then better he'll be ready to exchange 20 minutes of his life to welcome each new user. Actually what would happen is that someone would be welcoming a set of 10 users and not precisely the same set of users I did, because there is no way to reach them all with this approach, that's the difference with a bot.

If every user looked at each new user and made a careful decision about whether or not to engage based on common interests, etc. and then did engage in a meaningful manner, the system would be improved. Please consider the latter.

The common interest here is avoiding the feeling of entering a platform helpless, for those 89 there was someone (me) welcoming and ready to help on the firsts steps.

That's the difference regarding how bot's handled the "welcome service needs" and how a human can handle it. And there is no doubt that a lot of people here in steemit apreciates such a service, there is even people who miss Hive account@wang, I just fullfiled that need but the label of being a "spam" creator or "bot" is unfair, because the demand for that service is real and if it is done by a human that invests 20 minutes of his time to welcome onboard a new steemian there is actual some value added allthough you personaly can't subjectively see it, but others do and apreciate.

So I'm just asking for laissez faire, let me provide to that market...