So he's a late-stage, low-risk investor in platforms that are already established as successful.

Wow...what a visionary.

err... What are you citing?

He clearly's done a significant amount of early stage (seed and venture stage) investments both through A Grade Investments and in his own name:

http://www.crunchbase.com/person/ashton-kutcher http://www.crunchbase.com/financial-organization/a-grade-inv...

Using facts and citations to back up your point? You sly dog!