As a nitpick: Cloud Foundry isn't a company, it's an opensource project.

Lambda isn't, uh, quite as fully featured as Heroku or CF yet. And it ties you very closely to AWS. With Heroku you have a reasonable shot at migrating to Cloud Foundry or vice versa.

Disclaimer: I work for Pivotal, we're the major donors of engineering to Cloud Foundry. We sell a commercial distribution (PCF) and have a public service (Pivotal Web Services).

Good point. If startups are willing to pay much extra for a solution with vendor lock-in, the can certainly follow that path.