quick question

all day riding planes
not as bad as you might think
so what is the jinx?

Technically, I'm on vacation and I was going to not post for a few days, but I just had to pose this question:

Why is it that the 28-minute flight to Houston is on a brand-new 757 jet with video monitors and perfect cabin pressure, but the much, much longer flight to Atlanta takes place on a weeny 737, smells like a toilet and makes your ears implode?