> just unmatch the pair say after three days of the last message.

This is a good point. However, some women (due to men spamming them) don't have notifications turned on, so genuinely don't get around to seeing a message until they have time to sit down and scroll through the pile

Also (as I'm sure you know), anything that can be used as a "measure of cool" will be used as just that. And having a huge list of matches can be a huge self-esteem boost to some.

I agree with your point though. It can be tiresome to have to periodically clean out matches every so often