I mean there will still need to be spring-loaded pins somewhere in order to make good connection. And tiny pins means someone will bend them by accident at some point. And the pins are still a little involved to make, so taking them off means the RAM can be made cheaper. So this means:

• if just replacing/upgrading RAM, then no need for extra pins to be made
• if adding ram to a slot that didn’t have any before, then can also buy pins or they can come in some kits or whatever
• when someone bends pins, then just the pins can be bought for a reasonable price, instead of replacing expensive RAM, or very expensive motherboard