Our IT department has a policy of using the same computers that we sell to customers. This prevents us from being able to use Macs. Other than that, I think managers would be against buying Macs due to the issue of what happens if the person quits or resigns and a new hire is brought on? Will the new hire be able to use a Mac? There's also the issue of Macs being more expensive than Windows PC's, and the company may have a contract with a particular PC manufacturer that requires them to purchase a certain number of systems a year from them in order to get a certain discount. This also applies to software, Microsoft has licensing schemes that require companies to purchase a minimum number of licenses to get certain pricing.