Pilots succumb to "get there" pressure all the time, and this plane had a lot of VIPs on board, adding to that pressure.
I seem to recall reading afterwards that Ron Brown may have (did?) insist that the plane go to Dubrovnik instead of back to Zagreb due to the weather. Don't know if this was something that the pilots communicated in flight, or if it was just speculation, but it tracked your analysis re: VIPs...this was, as I recall, to be the last spot on their trip, and Dubrovnik is one of the top Croatian tourist destinations, what with all that Roman history and Diocletian's palace....
Absolutely. And more often than not, that "get thereitis" is a major contributer to aircraft mishaps.