You guys have clearly been brainwashed by the marketing department. (I'm kidding... sort of)
"You start in March and it's a double meaning!" Sure, I guess? Would you really argue against it though if they did actually update the ratings? Personally, I thought the whole thing was just a very obvious and not at all subtle way to make the laziest Franchise mode imaginable and then they decided on the name to ensure that they wouldn't actually have to do any maintenance or updates throughout the year.
... and for the record, I do enjoy the mode but there are so many things that irk me about it; this being one of them. And they do update the actual roster once or twice after release so it's clearly something that can be done. I can understand not updating after the Trade Deadline because that would make a lot less teams less fun and desirable to start one up with but I do wish that we at least had the option to choose for ourselves. Even if it disables Team Affinity progress then whatever... at least they'd be satisfying both sides of the argument here.