There's nothing viral about using GPL code. Your docker containers are probably running on Linux, which is also GPL, and that has neither infected nor affected you, has it?
I wonder how you could say such a patently (and copyright-ly) false thing, especially considering you replied to a comment explicitly mentioning Linux.
Would you not think all these huge companies would think twice before using Linux if it meant being dependent on the good will of everyone who ever contributed to any of thousands of packages that come with a typical distribution?
"I predict that the term "micro" will be replaced by the term "modular", and that docker will create a replacement for the microcontainer named the modular loader/container."
It's viral, any connection whatsoever, not sure where they draw the line. GPL is just not enforced except when it comes to selling software licenses.