I don't think they intend to be as out-of-date as they are. They are supposed to be around a version behind. So they should really be releasing 1.13 soon rather than 1.12.
They have had a few big tech changes in the 1.9/1.10/1.11 timeline so hopefully they will be able to catchup a little.
Yes, the reality is probably somewhere in between. We've heard that users like the idea that kops releases are more ready, where the .0 releases of k8s might have more issues particularly with ecosystem components. So we do lag a little behind - ideally one release.
1.12 has been a particularly tricky release getting everyone from etcd2 -> etcd3, but we've finally turned the corner on that one, so that should now let us catch up a bit.
Finally, we've also heard that users want more of a choice, so we're going to start doing e.g. 1.13-alpha and 1.14 alphas much sooner. We'll still wait to do kops 1.14.0 until everything is ready, but for users that want to run k8s 1.14 sooner, they will have an option that isn't building from source. And hopefully this also gets more people using pre-release versions of kops (in non-production environments) and also helps stabilize the releases more rapidly.
They have had a few big tech changes in the 1.9/1.10/1.11 timeline so hopefully they will be able to catchup a little.