No offense to the OP, but using logic like this to make a career decision is a mistake. The EWR 737 schedules today will not be the same as they are in 2 years, 5 years, 20 years. The same could be said for Spirit, where you work now.

This is akin to pilots that wanted to get hired by American when they had a Nashville base...that closed. Or that wanted to get hired by TWA because they lived in St. Louis...only to see TWA fail.

The decision to stay at one airline or move to another needs to be based upon the totality of information available about both companies, along with the best estimate of where each company will go in the short, medium, and long term outlooks. Focusing on one variable will inevitably lead to disappointment.