Well people can add to the "Feature Requests" topic at any time too, it's just that having it split into a separate forum with a topic for each request, instead of throwing it all into a single linearly organized topic (as opposed to "threaded" discussions on sites such as Reddit) is a lot easier to manage.
And people already do vote on topics with their +1 posts.
If that was a poll, it seems like that would be quicker to gauge popularity, since it keeps track of the total.
Even if that voting is just a poll with an option for +1 rather than a yes/no vote, it avoids cluttering up the topic with "+1" posts too.
It's not like you can't comment on topics with things like "a nice idea but too complicated for now" etc, similar to what you did in
this topic. (not that you would be required to)
I don't think it necessarily changes the expectations or workload at all, just makes it easier to keep track of requests.
It's not like we're asking for a public bug tracker here, just a feature request sub-forum.
I find it difficult enough to go back and find my own requests sometimes, let alone other people's in that big topic.