I think this is just some unnecessery whining of a leader that is not able to manage his group.
What is your Problem with Alts ? i know someone that atm manages about 4 acc on the same server, his own and 3 of ppl that stopped playing we all are trying to find players that want to play those acc, but sadly cant find ppl ( and yes we have the allowance of the original owners to search for other players that want em ).

For the person Keeping the Accs alive its a Huge time investment, and funny thing ... All those accs are in the top 20 of the server.
and as Far as i know from some servers if you would bann ppl with alts or that played multible accs on the same server... you would ban half of the top 50 if not more ...
you also would bann the ppl that are helping out with login rewards if your away on Holidays taht just log on get the rewards and do some dailys so YOU dont fall to far behind while enjouing your time off somewhere

My personal Opinion ... IP Ban for ppl with Alt / Multible Acc is just *... if you got a problem with spys manage your group better, or swap your Fields in the last secounds, but your spy problem is not worth killing of some servers