Concrete Ties haven't panned out so well in many locations. In the Powder River Basin the coal dust acted like an abrasive compound and as the ties moved underneath the loaded trains they ground away until they didn't have any holding ability. Resulted in a couple bad derailments before they realized what was going on.
Then there was the matter of a large unity of defects ties that were discovered. They company that made them replaced the ties, but the RR's ate the labor. It's not like wooden ties where a couple of guys could pull out a wood ties and swap in another one. Concrete requires a Speed Swing or Front End loader as a minimum.
UP also realized that you had to tamp the mainline more often on heavy traffic mains to keep the ballast tight against the ties. They were hung ho on concrete ties until all these issues start occurring. They're used much more selectively. I'm sure the other Class 1's have made similar discoveries.