Our Bishop moves pastors and priests around on a regular basis - kind of like an Episcopal version of "term limits". One thing it does is stave off this kind of thing.
Our rector has been here since forever (actually, since 1997 and part-time before that) but that's because he founded and helps run the parish school and the college (yep, an actual college, albeit a small one) here, and because he was in the Chancery and was diocesan administrator between bishops twice.
But you're right that keeping people in the same place for years does risk that sort of personal cult following. Look (if you can bear it) at that awful Fr. Pfleger up in Chicago that has been at St. Sabina's for 31 years. He's turned the parish into something like Jeremiah Wright's church, any resemblance to Catholicism is purely accidental. What a loon.