I can't speak for all spandex wearing cyclists but when I do that it is because I enjoy the scenery and the challenge. Are you equally frustrated with RVs?
> It’s a real sense of entitlement that is just beyond me.
You are the entitled one here. You have no right to a minimum speed on a road that allows cyclists.
> But if you’re leisure riding on a road where the speed limit is 55 and sitting in the middle of the lane you’re an ass.
I do this in all cases. If you can't get your vehicle fully into another lane to pass me then it's not a safe place to pass. If the speed limit is 55 that's a narrow highway and you have no exclusive right as a car. If you want that then stick to the freeways.
If a cyclist hugs the edge of the road then drivers frequently squeeze between the cyclist and oncoming traffic. If the cyclist stays in the middle of the lane then drivers recognize they need to wait for a clear passing opportunity.
Try it, you may just like it.