propably because there is a fine line between 'careerism' and
ministry, reason being (especially in the local church context),
most pastors here are full time church staff, meaning they draw a
salary from the church (they have family to feed too, right), so in
a way, its a career for them also.
yes, there are also a few 'tent making' pastor around (meaning they
have their own outside source of income).

*Note: the term 'Tent making' is term normally refering to the
example of Paul, who through his own tent making business, funded
his own work in the ministry, its not a ministry per se nor is it a
must that all pastor make tents nor that pastor must fund their own
ministry.