Probably the reason they don't allow pre-1800 coins in the 7070 registry is because the Dansco 7070 didn't include any pre 1800 types. (Although I do believe it did list the earlier dates for those types that "bridged" the 1800 date.)
Ya know, when you write it like that: "who cares" more than once, it gives a very negative connotation. In my experience many people who participate in the registries care, including the OP. If he didn't care, he wouldn't have taken the time to create this thread. Working on and completing a registry set and sharing it with others can fill you with pride and a sense of achievement. Winning an award for either a top ranking set or best presented set provides an even higher sense of achievement. So while I agree with your sentiment that registry points are not the end all be all, and that they should not restrict someone from collecting a coin that doesn't fit in their registry set, that shouldn't relegate the registries to the "who cares" category IMO. I have long said that you can search the registries and within each series you can find the few individuals who have a passion for what they collect. Here are a few examples: Physicsfan3.14 Prooflike Type Set (7070) Skymans TonedBennies and of course my set: I just wish there were more collectors who liked to photograph their coins.