There is a cottage industry that actually do just that: create a wrapper program with nice gui to prepare data file input and read/visualize data file output from an open source fortran model. For example, aermod is an open source air pollutant dispersion model developed by EPA and there are a bunch of commercial GUI wrapper for it because (as you note it) you can't expect scientists without computer science background to compile, prepare data and parse the output of a fortran program. Those thing are hard to do in fortran as a programmer, let alone as a scientist without computer science background.