You are likely confusing cause and effect. Comair was having issues before the union got involved. The union simply made the companies failure more obvious.
Also, no matter how you look at it. The result of the failed negotiations was them selling 90 planes to pay for the stewardesses. This resulted in the furloughing of 90 planes worth of employees, and ultimately in the company not being competitive enough to survive.
I saw this front and center as someone with no real view for or against unions sans the union dues were forcibly deducted from my salary whether I wanted to be in one or not. I came out seeing the teamsters for what they truly are. The teamsters unions are the thugs they were formed to prevent. They need to be broken up.