Even though I'm a huge fan of JetBlue, I've noticed the decline in customer service as well.

Having gone over the fence to the other side, I've also noticed that despite JetBlue having great amenities, the crews on Delta are better. Why? Delta's flight attendants are warm and genuinely seem proud to be working for the airline when you hear their announcements. Meanwhile on JetBlue, the majority of flight attendants are 20-30 somethings coldly reciting a script.