I think it would be useful. You could try matching people here on HN.

If you want to match similar people, aim to make them as geographically as close as possible. What you really want to find is "uncommon commonalities" between people and build groups around those. So yes, like attracts like, but it can be surrounded by stark contrasts as well. You could grade a match - percentage different, percentage same and then add some strength/idiosyncrasy/geographical/group-match weighting.

The progress bar at bottom of questions: it says "keep going" but eventually it reaches the end and there is a page refresh without any user confirmation to do so. That can be confusing and distracting.