My interpretation is that Connect is(/was?) a programme aimed at enticing new customers to create GOG accounts. As a new person you could start an account here with something already on your virtual shelf. As existing users we benefitted from that (which was great!) but I honestly don't see us being the focus. It's a store not a club after all.
Since someone somewhere is losing money if you give away games like this (since rebuying is a thing), they shouldn't do it unless it generates more new customers to regain that lost income through additional sales.
Where it back-fires for them now though is I've become reluctant to rebuy here in case it turns out through connect I could have got the same thing for free. I definitely would have spent more in the summer sale if connect didn't exist, however I'd wager they'll make more from a new customer than me.