You're saying spiritual things can't be literal? What you're really saying is one side sometimes sees things as having a spiritual reality while the other sees them as having a physical reality. Either way, they are real, literal events, though. Just because something is spiritual, such as what happened on the day of Pentecost, doesn't make it non-literal.
Also, the foundation of Amil doctrine is based on straightforward, literal passages such as Matthew 28:18, Acts 17:30-31, John 5:28-29 and 2 Peter 3:10-12, so it's not a fair characterization of Amil to say that we just spiritualize everything.