His argument was that a game that is remotely difficult will scare people off, resulting in a lowered population that will hurt sales down the line. The obtuse mechanics that make the game remotely difficult being combo's (is this really that difficult) along with glitches and others. I pointed out various games that are either incredibly difficult, not easy to get into, or have glitches that were never taught that have had thriving communities in those games and grew down the line. Halo grew. Gears grew. Dota grew. League hasn't had successors, but it's become massively popular and doesn't show signs of stopping.
He refuted it saying that those are team games and teammates will be able to show you what you're doing wrong. Besides the obvious fallacy of those games all having equally poisonous communities where a teammate is as likely to piss in your eye as help you (if you're playing with a friend in one, chances are you'll play with one in Smash too). I compared it to Smash FFA's (which allows you to play with a friend or someone that could help you learn, on the off chance that this community isn't as poisonous even though we know it is), and Smash teams, since Smash has those modes too and he was claiming that it was mostly in 1v1 he was talking about.
Even there, you can look at StarCraft 2 or other fighting games. SC1 was popular for 10+ years and only died competitively a year or two ago. That game had obtuse mechanics up the butt. You could only control 8 units at a time, the AI on scarab drops was confusing as hell, etc etc. I don't know as much about the FGC, but thinking that a game having as high as a skill ceiling as melee will detract from sales down the line is ridiculous. Halo 3 sold better than 2, Reach was shit, and so was H4, yet both sold on the name alone. SC1 sold great and SC2 is doing well enough to merit 2 expansions. Smash will continue to sell well on the name alone, and claiming that making it have a higher skill ceiling will scare people off is ridiculous.
edit; This convo's dying off and I have class in the morning, so peace.