Hate to break up all the idle speculation with actual statistics, but ...

http://www.rita.dot.gov/bts/press_releases/bts013_14

Short version:

• From 2007-2009, there was a big drop in US passenger traffic (roughly 50 billion passengers out of a total of 830 billion). However, that time period also coincides with the recession in the US, which might be seen as a better explanation for the drop than dissatisfaction with the airline industry.
• Since 2009, there has been steady growth in US passenger traffic (roughly 1-2% each year), to the point that current traffic loads are approaching the peak reached in 2007.

Of course, one could argue that this growth rate could have been higher with a better traveling experience. But that would be sheer speculation. One could just as easily argue that the imposition of "security theater" had an effect on increasing passenger traffic, since it provided emotional reassurance to those for whom security theater is designed to impress.

In short ... the raw data doesn't really support a conclusion that bad passenger experiences has lead to a decrease in passenger traffic.