By way of agreeing with you I will say that yes, easier for IT is "better" than easier for the users, and this has nothing to do with PCs and Macs, it has to do with the fact that there is no spot in the company's financials for the time and efficiency lost by products that do what they are supposed to do, but do it poorly.
Whereas, it's easy to measure the amount of time IT spends supporting the product. So if there are two different UIs, it's easy to see that you need two different training sessions for users, but hard to measure how much time the Mac users lose struggling with the UI.
As I said, this is hardly a Mac/PC thing. You often see it in horribly designed internal applications. It's easy to measure the cost of development but hard to measure the productivity lost due to craptacular UX. So in 2011 I still see RFQs from clients asking for search pages where you fill in a complex form indicating which field you want searched and how to search it, instead of implementing a single full-text search across the application.
You are missing my point, and that could very well by my fault in not explaining it properly.
Why should an end user, who could use multiple platforms, need to understand two different layouts for the same program. This has nothing to do with different vendors, but the fact that a company needs to invest serious time in to developing a UI that is intuitive in all platforms they are targeting. The user experience should be well thought out so that it is a great application that takes advantage of the operating system interfaces that they are working with. If that user experience is lacking then someone dropped the ball - which is a burden for end users, IT folks and so forth.
