The original version of the movie tron should have propelled the field of cgi except for the fact that:

The Tron movies did not make as much money as Disney had hoped. It was over 100 million to make the movie, however they only made 400 million back. It may seem like a lot but another movies (Alice In The Looking Glass) was also released that year. The movie was around the same price to make it, but it pulled in 1 billion USA dollars. Much more.

~Hope this helps!

answer-the island had airfields that the u.s. military needed.