I've been to Labadee about a dozen times, starting when it was a new stop in the 1990s up until last year, and I'll be stopping there two more times in the next few weeks. Indeed, the change from rustic spit of rock and sand into what is a lovely resort has been profound. It is a favorite stop for me now, and yes, like the others I didn't care for it much in the early days.
The poverty beyond the gate would be there regardless of whether Labadee existed, and in fact it would be worse since the resort provides good incomes for many locals. I don't dwell on it when I'm there. I do try to tip the locals who do things for me. A marching band of local kids - sort of like a high school marching band - plays during the day and I note that RCI provides lunch for the band during the passenger lunch, which is likely part of their payment for playing.
The dock definitely improved things as far as logistics. The sole reason was to accomodate the Oasis class ships but since it is used by all the RCI ships - as well as the occasional Celebrity cruise stop - it has been a great addition to the port call.