Once Linux is juicy enough it will be the new target.

People have been saying exactly this for 20 years now, and it still hasn't happened: organizations still entrust Windows with all their sensitive data and critical services. The fact is, if these victims had been on Linux instead of Windows, they would have been mostly immune to attacks, certainly to these ransomware attacks that only target Windows.

Remember, when you're hiking and you're attacked by a bear, you don't need to outrun the bear. You only need to outrun the slowest hiker in your group.

Linux is way harder to target, as any software vendor will readily tell you, so it would need to be significantly juicier for worthwhile return on investment.