I don’t find it odd at all that conservatives hate it when the national party endorses a moderate candidate in a contested Republican primary. The point of elections is for ordinary citizens to decide who they want to lead them. Elections do not work correctly when a national party dictates to its members who will be their nominee. This is always a problem, but it becomes acute in open primaries. At least with incumbents, they are paying dues and have a right to expect some support from the party. This idea that non-incumbents can make it a condition of running that they get the endorsement of their party and that an effort be made to clear the field of strong opponents, is not a good one. In most cases, candidates emerge stronger for the general election after winning a tough primary. It does waste money and it can cause schisms that are slow to heal. But, overall, the challenged candidate fares better than the anointed one. Ask Barack Obama.
