If you are short sighted enough to only care about day to day operations and don't see competence in software usage as an investment that will bring competitive advantages in the long run.
Your competitive advantage is your staff, not your software. A company like Pixar only has so many proprietary tools because they've been around so damn long that rolling their own was the only way to go to get the results they wanted.
Even then, Pixar's advantage was the people they hired and allowed to thrive... not Renderman.
