Which is all very well, but it happens to be true that there's very little for a priest to do with gold except put it in a temple (or guildhouse) or give it to someone else. Any other noble class has troops and paraphernalia, which need pay on a regular basis.
Thus, 99.9% of the time, priests are not expected to be carrying massive amounts of money around.
Furthermore, the fact that this incident is so noteworthy should tell you that it's not exactly a common thing for you to get attacked...and if you make a habit of carrying around thousands and thousands of gold, you should already know that it's not even common for that circumstance.
No one, so far as I can tell, is calling for it to be more common for bandits to attack you and steal your gold. But I haven't yet seen anything that suggests that it should be less common, either.
Once again, you're completely ignoring the Diplomat subclass. You know, the one whose abilities are almost completely driven by gold? The one that most priests take as a matter of course because it's the only subclass worth taking for a priest? Yeah, that one.
