JetBlue is getting the short end of the stick by buying Spirit Airlines, and it's not just because of their terrible customer service. JetBlue will be forever burdened with a struggling international carrier that makes up a large percentage of its revenue. The article describes why the purchase is a bad idea for JetBlue and what they should do instead. What is the Deal with Spirit and JetBlue When Spirit Airlines Flights Booking announced its purchase of JetBlue, it was seen as a move to increase its market share. They plan on using JetBlue's service and adding more destinations, but…