The merger announcement with F9 was Februaru 2022. The landscape was substantially different then and NKs financial position is much worse (orders of magniture worse) than it was in early 2022. F9 was buying NK mostly by issuing new stock (with some cash) but NK had almost $1.7B in cash on hand plus access to liquidity and hadn't sold a bunch of planes to generate cash yet. This is from NKs 2021 Annual Statement

"As a result of these actions, as of December 31, 2021, we had $1,679.8 million of liquidity comprised of unrestricted cash and cash equivalents, short-term investment securities and funds available under our revolving credit facility due in 2024"

F9 would have taken that cash to add to its own as part of the merger. B6 was offering a "cash only" purchase, which is better for shareholders because they don't get issued F9 paper which would have been diluted. Also those noted due in 2025 were still over 3 years away and both F9 and NK had ample cash to cover them.

Also NK didn't have a -30% profit margin (loss) and hadn't sold a bunch of planes to keep the operation going.

The situation is MUCH different today than Feb 2022 which was 32 months ago.

Stopping a slow rolling boulder is easy to do, but at this point the boulder is in a freefall and will crush you if you try to catch it.