Why not install solar panels all over your facilities? Solar can be complex and expensive (>3yr simple payback is intolerable for many companies), and if you live in an area without a lot of sun, it might not make sense. With the pain of installing wind turbines, that might not work either.
The trouble I've seen in practice is that employees and company executives don't buy into the additionality of the project, thus rendering the money in the same category as snake oil and used cars. How do we know exactly what we're getting? What is the business benefit? Why throw money at an external project when we have internal capital needs. Answers to these questions are tough to pin down.
On the positive side, these decisions and the discussions around them at least raise awareness about the intricacies of renewable energy projects and practicalities of carbon footprint improvement.