What's would they have had to "sacrifice" in terms of character and run-time by leaving the Squid in. They just have the dead squid sit there in NYC. It doesn't "do" anything. It's only in that one scene.

Unless they're talking about remoing Veidt monologue where he talks about the squid/unveils his plan, If so, that's a HUGE ommission which makes the whole movie almost pointless.