In short yes. There are newer tools coming on to the market that offer much better tactical and strategic fuel decision making methodologies.
The FMS is a good tool to fly the aircraft using a strategic method for optimum profiles generated by better tools like a flight planning systems. The problem is that the data sets that pilots input and the loaded data coupled with poor algorithms in todays FMS's results in bad information to use to make inflight decisions.
Given the time and cost to build and implement new and better FMS systems, the best solution is to disconnect the tactical and strategic decision making from the FMS and use the high powere and fast changing technology in PC's or tablets for this kind of work.