The plane itself is not "fucked"; my understanding is the aircraft landed safely and nobody was injured. The door/window that departed the aircraft is a serious incident that will be investigated. There will be a report produced that identifies the root cause(s).
>How does the maintenance crew fuck up a plane this badly in the span of two months?
Are you under the impression that aircraft maintenance works like car maintenance, where you just change the oil every so often?
Lots and lots of things get removed and replaced on a regular basis. It's entirely possible somebody just didn't install the door properly after removing it for a routine inspection. It's a big deal and a serious incident but these things do happen from time to time, even at name-brand airlines.
I'm all for lambasting Boeing but let's stop frothing at the mouth until we see the report.