The "trick you to download and open" thing can be done on any system, as long as the user has sufficient privileges, and is willing to follow the instructions. Even the joke "Aggie Manual Virus" email will work if you do what it tells you to. "Forward this email to everyone in your address book then format your hard drive."
The .jpg exif exploit in MS Windows would have scared me if it transported to Mac.
You've seen one Mac virus, you've seen them all. Sure can't say that about Windoze.
Me, I like Unix, and have for the last 20 years....