I don't think it would be as easy as you suggest, especially if they want to integrate the points accounting with the room assignments. The current system tracks each original contract and their add-ons seperately, you have banking and borrowing, trade outs through various venues, assorted types of holding accounts, reservation changes, cash nights vs. points, housekeeping scheduling, CRO Cash ressies then add to that room preferences in a very fully booked resort then it also has to accomodate HA rooms, smoking and non-smoking, views, vicinity (close to check-in, close to bus stop, 1st, 2nd, 3rd floor, etc). Now, try to dumb that system down to be placed online for "Average Joe, I just bought a computer and have no idea how it works" to use without problems.
Overall, a much more complicated program than a similar "cash based" resrevatin system.