So why not just create a Chronicles-alike with new cards, which just so happen to be mechanically equivalent to the Reserved List cards?
I've no idea why that isn't done for magic so collectors can collect rare originals while players can build decks full of lotuses and moxes and whatever other powerful cards they want so they can compete on skill, not wealth.
There are also differences allowing you to pick an Alpha from a Beta from a 1st Ed.
4th edition onwards, the reprints have a white rather than black border.
The Lotus and Moxes were discontinued after 1st Ed for being too powerful due to their zero casting cost. Instead you have cards that will cost you life and at least some mana to cast so it's not game over first turn.
Creatures have mana cost (1 mana, 2 mana etc) in the game. To play creatures you need mana and mana cards can only be placed on the board 1 per turn. this means usually a deck with a some creatures having 1 mana cost so you can hopefully play them turn one, some with a cost of 2 for turn 2 ... etc.
Black Lotus let's you get 3 mana when you play it. So you can put serious pressure if you have a BL because it's basically "turbo" and let's you put bigger creatures on the board "earlier" than normal. (In theory a creature costing 6mana wouldn't come into play until at least turn 6 because of the 1 mana played per turn.) There are also ways to use cards that copy other cards abilities so if you copied BL you could make a lot of mana fast. That "breaks" the game because everyone would start to use that tactic and you'd get a less diverse metagame.
If WoTC made a "red lotus" that did the same exact thing as BL, the value of the Black lotus would drop (pissing off collectors) and they'd have to restrict this red lotus the same way (You can only have one BL per deck in the current rules) or the red lotus would end up more valuable than the black because it wouldn't be restricted to one per deck and people would want 4 of them. (the max of a regular card per deck.) This would also probably piss off current players because it "broke the meta" and would be expensive.
The reserved list isn't the best solution in the world but it's pretty solid to avoid making even more people mad. Most people that have "invested" in a BL are still playing magic or involved in some way so why make them mad?