Yep, and there are still plenty of large areas west of the Mississippi -- nearly the entire state of Montana, for example -- that will still have no T-Mo service at the end of 2015. Contrary to popular belief, people do actually live in Montana. And many more people vacation there.
Is T-Mo getting better? Yes. However, I take all carrier maps with a grain of salt. Having used every other major carrier except T-Mobile over the past 20 years, my experience has been with each of them that there are places where the carrier's map shows that there will be coverage when in reality, there is either no coverage or unusable coverage.