It's really simple. Whenever a new competitive map is introduced into the map pool, people are afraid of playing it and losing their rank. Unless you're really into new experiences, there is no incentive to try our these new maps.
Obviously Valve could go for an actual solution - introduce every map to scrimmage, and limit the "unticking" in Competitive to two map vetoes. But apparently both Valve and the community are okay with third-party companies doing Valve's job, so we need to improvise.
So basically, you introduce a new map to the map pool? Double-drops for a week when you play it. Hell, every week pick a random map and make it the "double drop" to incentivize rotation.
