There are at least two schools of thought when it comes to playing retro games. Let's call it two for the sake of argument. On one side, there are people who want all the modern conveniences, both in-game and out: save states, fast-forward and rewind in the games, and wireless controllers, high definition output, and non-finicky hardware to play them with. These are the people who like emulation the most, either through downloading ROMs or official downloadable re-releases of games.
On the other side, there are people who strive for absolute authenticity: real cartridges on real consoles, played on CRT televisions with real controllers. These are the people who, hypothetically speaking, stuff a Twin Famicom in their suitcase while on a business trip to Tokyo.