In that case the instance you’re on is basically the block list, right? That’s good, especially if most instances are really dedicated to stamping out that kind of thing. But if/when Mastodon gets big, it becomes a problem of scale.
In practical terms it’s kind of unrealistic to expect T&S to deal with people because they have garbage takes; most of their day is going to be dealing with the usual internet nightmare sludge, which is where I think block lists become a real utility on the user end of things. In addition to the advantage of just making the blocked users shout into the void when 90% of the site wants nothing to do with their ass, which I can tell you from observation makes them extremely mad.
Alternately: a 1 hour old account may not be entirely truthful about why they were banned