What do you mean by the bolded?
As far as value goes, is being able to track stats valuable to the competitive scene? Is it something casuals like to do? I think so for both, but enough to go online only? Not sure, but I don't think casuals would be as concerned with online only as the FGC would be.
Simply that if the game is by a big-name company and/or is a well-known IP, more individuals at pretty much every level are going to give it the time of day. More on-the-fence consumers will try it, more reviewers will give it a cursory glance, business heads may look to its success or failure when planning other products, etc.
Stat tracking could be valuable to competitive heads and to even casuals; the NFL is an easy mark for this. Plenty of people like to see stuff like representation lists and tier lists; Dahbomb's tournament perf. tracking for example gets a lot of attention in FGC-GAF.
EDIT: Or like that eventhubs database that I probably won't get to see because I don't know if Akuma is a weak character.
Also, if a program is good enough at observing trends in a player's personal stats, hypothetically it could then put that information to use if that player wants to train and improve. I think that is a possibly big step to making the genre more accessible; that is, making the 'lab' an accessible concept to people who don't know where to even start.
I'm not sure if any of that justifies always-online though. I'd say it doesn't, since none of it really says "this is why I always need the Internet to operate". It's a harder argument to make than the one RTSes and MOBAs have to make; MOBA-type games were essentially birthed on a perpetually-online platform, and no company that makes fighting games today(even Capcom) has the clout Blizzard exercised when it killed the option of offline LAN play starting with SC2 and got away with it.
I think that if you're making an always-online FG, right now this means that you are simply not targeting the same audience traditional FGs are. Obviously there is some overlap, but it isn't the same thing.