lets stop that right there.
That is most certainly untrue. Its incredibly easy to be bad at SF, depsite playing it a lot. Now if you play that much, most likely you'll take the time to look up the information needed for you to play well. But let's say you didn't just for kicks.
If you didn't look up information, you would probably never figure out, for instance, abel's mk -> forward dash -> whatever. You would never know that you can cr.mk xx Change of Direction. These are things that you need people to tell you, and playing a lot would never teach you that. That's just 2 examples from one character but there's plenty for each.
The same happens in melee, a game which i played competitively (and still do when i get the chance). There are people who play that game for YEARS that I can wallop on with no effort at all. Their experience doesn't teach them anything, because its not on the proper level of competition. They don't understand why mewtwo is bad, or why short hop lasering is worthwhile. And unless someone teaches them (or they teach themselves) they never will.