Git itself (as I'm sure you know) is a free tool, and learning git is a worthwhile skill no matter where you are using it. Hell, I know people who use git for collaborative document management.
And the SSL stuff and domains offered through namecheap are going to be helpful to anyone who wants to go into web development. Knowing how to set up a domain, with proper DNS records and SSL configurations, is a pretty basic task for people who do web stuff. And, again, these things are platform agnostic. I think there is a lot of value offered here, and not all of it serves the purpose of furthering vendor lock-in.
You can one-click-deploy a LAMP stack from DigitalOcean lol.
Honestly this offer is just like those gigantic coupon books you get in the mail that gives you discounts to all the local area restaurants (that paid up). It's great if you want a good deal if you want to go out, but it's not like anybody's doing you a favor.