The leaseholders just want the planes back. They don't care, need or want to liquidate Spirit. The BK was filed to keep the lessor from taking the planes. NK can't just use BK to sell those planes to facilitate some value transition into another company. Leaseholders don't need a liquidation to take their planes back. There is strong leasing demand for planes worldwide. Especially in Asia (according to Aercap, the lessor). Spirit also owed $72M in fees to the lessor for cancelling planes they were supposed to get in 2027 and 2028 and is in violation with its lease agreement from a bunch of existing leases.

The creditors have secured debt. I'm not sure why they would want to just "roll the dice" and give that up for some equity in the next possibly bankrupt airline that can just wipe out their equity with a BK. Spirit has about $400M cash plus the $275M in revolving credit they just pulled. I imagine that much of that would just go to the bondholders, plus the proceeds from whatever assets they could sell.

If Spirit management came to you and said "We won't pay you any money but we want you to keep flying planes and we will give you stock in Frontier that's worth 19% of your current monthly wages and you can't liquidate it for a year, would you take the deal?