Haha, wait, 6/4 Mario, that means we win 60% of the time?
You guys haven't played any good Marios, which isn't surprising, he's low tier, just like how most people haven't played many good Falcons.
Well a buddy of mine mains Yoshi and Mario, and I'll tell you what, Mario ***** Captain Falcon. As people have said, fireballs and cape. I can do well against Mario if he approaches me, but all my friend has to do is start playing more defensively, and it becomes impossible. Fireballs can stop just about any Falcon approach. Ground, air, over the ledge, anywhere. And recovery games are almost lost on Mario. Every time you recover you have to go either very low, backwards, or very high. If you try coming near him you'll get caped everytime (if the Mario is good). And when Falcon's recovery gets caped, he's pretty much dead everytime.
His approaches are good in most cases as well, again, because of the fireballs. Fireballs can lead into combos for Mario. Also, when Mario is coming down from the air, Falcon doesn't **** as usual, mainly because Mario has some great moves with big range, such as his dair and fair (I swear dair will stop any move you try on Mario in the air). When he's below Falcon his uair is very good as well, and comes out fast, even faster than Falcon's.
Also, he can get jabs out between our jab>jab>grab combo before the grab if they time it well enough, which is a crucial part to Falcon's game.
He's also good at finishing, with his quick stutter fsmash, which can nearly be combo'd into.
Trust me, you all haven't played a good Mario, much less one who knows how Falcon plays I'm sure. Don't even try to pull online crap either. Mario has priority, range, and gimping on Falcon. Every one of his strengths pretty much applies to Falcon. I'd say the matchup is easily 30/70 in Mario's favor. It's an uphill battle every time I have to face him. I may try making some videos sometime for you all.
EDIT: It looks like most people were saying 60/40 in Mario's favor, which is much better. Really I'd still say 70/30. There are many characters I'd rather face as Falcon other than Mario.