The thing about Gmail labs is they are (mostly) extra features that you could use or not, and which didn't leave you worse off than if you'd never used them if you started and then they were killed off

Fully fledged products have more risk. And I've felt burned by multiple Google products in the past.

Let's say the first product announced by Area 120 turns out to be a great new chat app. Would you recommend your friends all download it and start using it? :)

Edit: Confused Google Labs and Gmail labs, my bad. Removed nonsensical comment.