The main reason Ice Wall got removed IIRC was skill abuse to grief people, same as Bio3. I really dont like this reasoning, although with how overworked the support staff are right now it's hard to say how interesting things would get if certain players were given the opportunity to endlessly grief others again.
I dont think it was entirely a nerf to make people killing things harder (although for some of the harder MVPs this may have been the case) but there was a small group of people teleporting anything they were being comped on early on in Classic.
I dont mind either being in honestly, Ice Wall makes things easier to kill/setup and prevents multiple time consuming resets to get things done. It's a little silly that you can take a few boxes of tokens and kill stuff though.