Macs and IOS still get hit, but much less.
Many factors include lower user numbers (MacOS specifically), but on the IOS front the 2 main reasons are that Apple locks down installation of software to what you get on the app store only. It's very hard to get nefarious apps through.
The biggest reason for Android's vulnerability is the fragmentation of OS upgrades that mitigate a lot of risk. For example, when a new IOS comes out, the adoption rates are insane. Within a few months ~80% of Apple users could be on the current OS. With Android, as the article says, software updates are often manufacturer specific. So while Samsung and other big companies might have the new software really soon, there are dozens of others that might never get the updates, despite being quite new. That's pretty damaging to the stats overall.
This from TechCrunch kind sums it up...
"Despite this delay to notify users, now more than half the active user base moved to iOS 10. For comparison’s sake, Android 7.0 “Nougat,” which arrived several weeks ahead of iOS 10, is only installed on 0.1 percent of devices."