@exyle,
This is absolutely true and I also feel this is little complex scenario, because there are millions of transactions happens daily and if someone send funds without adding memo description it might be a CHAOS :/
At this point I have a respect on Poloniex. Yeah what they are doing is correct and it should be happened too.
Thanks for sharing such valuable post! Really appreciate your effort and this is a very useful post for minnows of this platform!

Cheers~