Bon Jovi touring more often is not really a viable explanation for the fact that U2 are a bigger touring act. Look at the Latin American figures. U2 had previously visited Latin America in 2006. Bon Jovi's last visit had been some time in the nineties. So decreasing demand due to overtouring is not at all an issue here and U2 still vastly outgrossed BJ:

U2 2011
Attendance: 802,264
Gross: $83,721,355
Shows: 10
Average Gross: $8,372,136
Average Attendance: 80,226
Average Ticket: $104

BJ 2010
Attendance: 245,295
Gross: $20,935,176
Shows: 6
Average Gross: $3,489,196
Average Attendance: 40,883
Average Ticket: $85

The same goes for any other market U2 have been touring more frequently than Bon Jovi (Spain, France, Italy, Belgium, Denmark, Sweden, Poland, Wales...) and countries that both artists have visitied for the first time or after a long period of time (South Africa, Croatia, Turkey, Greece). This "touring more often" issue is certainly not a sufficient explanation for U2's superiority in terms of touring, as it is invalid for so many markets.

As for the US, touring an arena every two years in a particular city, serving a core base of approximately 15,000 - 17,000 each time, might slightly reduce your drawing power on the long run but do you really think Bon Jovi would be able to play, for instance, Rose Bowl or Cowboys Stadium if they waited another 4-5 years before touring? In fact, they have never once in their career been able to tour stadiums in the US comprehensively. U2 have multiple times in their career, so have the Rolling Stones, Bruce or Pink Floyd - For BJ, however, it's always been a handful of shows in the northeast. Don't you think there's a reason behind this other than "So they chose to play more small shows instead"?