It's what I call "the Mac tax."
Programs like Family Tree Maker, Quicken, MS Office, and others, cost MORE on the Mac and they actually do LESS than their Windows counterparts. And this always includes upgrades that are more expensive than Windows equivalents, too.
There are some better genealogy programs for the Mac, in my opinion. For instance, I really like/liked MacFamilyTree much more than Family Tree Maker for the Mac. However, I also like having a current tree on ancestry.com and I don't want to do double duty to keep both up to date. I really like the syncing feature.
Earlier this summer, I tried running the Windows version of FTM in VMWare, but every time I tried to work with it, I was reminded why I don't like using Windows, so I switched back to the Mac version.
Honestly, I wish Ancestry.com would sell Family Tree Maker to a another company and then release an api for third parties to sync their software with the trees we have online. That would give us much more choice and freedom.
But I don't see it happening anytime soon.