When I was in college a teacher said "if your IT project doesn't have executive buy-in, its not going to make it to market/production". Over the years I've learned this is just so very true. Its not usually the IT managers that pull the plug, its the executives outside IT that do.
Years later I worked at company where all the senior developers, senior DBAs and senior project managers were assigned a huge database project. They worked on the requirements analysis, back-end details, etc for a year, then started in on the development. At the end of that second year the whole project got cancelled and all of them got laid off ... all the senior people ... laid off.
The problem was they assigned themselves this huge project. They dreamed up this huge grandiose system, got a budget from an executive who left the company shortly thereafter, but then they never got any buy-in from any other executives. Two years and probably a million $$s into the project none of the other executives knew anything about it, didn't know what it was for, and when they looked into it, didn't see the value in it. So they just cancelled the whole thing and laid everyone off. Poof ... gone !!
By that time all the other development work was being shipped overseas anyway (to Romania). So the company probably saved a million $$s that year by getting rid of all those senior people.
Executives don't have any issues cancelling a project they don't see the value in.