Okay, I know this is beating a dead horse, but they do have to put a certain amount of time and testing into these ROMs to make sure they work, right? So there's a certain time investment, and the reward is having an attractive perk to purchasing Nintendo Switch Online that drives people who might otherwise not have bought it to do so and that drives people who might not resubscribe to do so. Some time for some money. Which means that the more attractive they can make the NES Online service without significantly increasing the amount of time put into the service, the better for them.

As a thought experiment, let's say that an NES game takes 5 energy points to add, setting up an SNES emulator takes 10 energy points, and an SNES game takes 5 energy points to add, and we'll assume Nintendo is allotting 10 energy points to the project and any extra energy points have to come from some other project. Let's also say that a very popular game like Super Mario Bros. brings in 10 popularity points, a somewhat popular game like Kirby's Adventure brings in 5 popularity points, a game that hasn't aged well but that some people played back in the day like Dodgeball brings in 2 popularity points, and a game that nobody has ever heard of, regardless of quality, brings in 0 popularity points. Currently, Nintendo could keep putting in 10 energy points for 2 NES games, but they've already released most of the games in the 10 and 5 point categories. That means they're scraping the bottom of the barrel of their back catalog, so 2 and 0 point games. Currently, they're putting in 10 energy points and getting 4 popularity points back at max instead of the 20 points max they could get near the beginning of the service's lifespan. The SNES library's collection of 10 popularity point games is completely untapped and could easily be drawn from for another year before even getting to 5 popularity point games. By continuing with their current plan for the next year with their current schedule, they would get at max 48 popularity points. If they dropped down to one NES game for the next two months and put the rest of their allotted energy into testing an SNES emulator, they would make 4 popularity points through August and September instead of 8 (at max), but would make 200 popularity points through the rest of the year from releasing beloved games like Super Mario World, leading to a total of 204 instead of 48. Of course this is a flawed thought experiment since I don't have Nintendo's budget in front of me and I can't actually quantify people's desire for games into numbers in a clear cut way, but I still do think that the general idea it conveys, that Nintendo gets more from putting some effort into the SNES emulator once and reaping the benefits for the next two years by releasing games that people are familiar with than from releasing games nobody has ever heard of from their NES library for the next 12 months, specifically because the point of the NES Online app is to make the online service appear more attractive and games that nobody has heard of don't make the service appear more attractive. By investing just a little bit more in the short term, they can gain a lot more for the same energy cost for the next 1-2 years.