Don't know if it was marketing material when you published it in that whitepaper, but it definitely became marketing material when the @Docker twitter account tweeted it (https://twitter.com/docker/status/768232653665558528).
I don't think the material you're referring to qualifies as criticizing competitors at all.
- The comparison table is part if an independent study, not authored or commissioned by Docker.
- The table shows the strengths and weaknesses of different container runtimes; weaknesses are highlighted for all of them, including Docker
- The table is used in Docker material to illustrate the point that independent security researchers consider Docker secure. Nowhere do we make the point that other products are insecure. I encourage you to read the whole material and decide for yourself.
- The context for this material was to respond to a massive communication campaign painting Docker as insecure.
Even when written, the study made inaccurate claims about rkt (the SELinux support in rkt is identical to that in Docker, because rkt uses the same code from libcontainer - there is literally no difference there). It certainly wasn't an accurate depiction of rkt's state of security as of August.
(Disclaimer: I implemented some, but definitely not all, of those security features in rkt, and I currently work at CoreOS)
Come on. This comes across as entirely disingenuous.
"This was independent, not authored or commissioned by us." - "the fact that we posted it on our Twitter as "why your containers are safer with Docker", posted a lengthy blog article in no way means we were criticizing competitors..."
"Nowhere do we make the point that other products are insecure." No, just "less secure".
"The context we were in was responding to a massive communication campaign ... " - so you were responding to criticism by what, exactly? Oh, yeah, that independent study that you just decided to post about?
http://img.scoop.it/vr-SoyYI8yKYsOf0vxriWrnTzqrqzN7Y9aBZTaXo..., from http://www.docker.com/sites/default/files/WP_IntrotoContaine... (page 9)
Don't know if it was marketing material when you published it in that whitepaper, but it definitely became marketing material when the @Docker twitter account tweeted it (https://twitter.com/docker/status/768232653665558528).