@Zero I would think that a certain cards' qualifications, if you will, would be based off of the impact it had on the game at the time. Of course 99% of the classic sets would be horrid in this format, but back then there were obviously some cards that stood out. I can almost guarantee that after next rotation (which should be RR if they are starting a consistent rotation), Luxray GL Lv x will lose most of its value.
To go off the baseball analogy, you can't really compare players because baseball, as a game, has gone through several eras. The year of the pitcher caused a major change in baseball rules, including lowering of the mound. How would some more modern HoF pitchers do if they played on a lower mound? What about those just on the brink, would a lower mound have made them HoFs? The game (both baseball and pokemon) changes over time, and what is good today won't necessarily be viable tomorrow. One would have to look at the meta the card was played in to consider its HoF value.
A final example: before Babe Ruth, a 20 HR season was considered INCREDIBLE. But nowadays, hitting 20 HR's and doing little else will get you platoon time. (a la your Sneasel and Luxray comparison).