Its irrelevant to this conversation because BFW was saying high level players don't know how to make a game enjoyable for the masses and specifically cited micro discrepancy as the reason, which does not exist in a card game.
The point that IpKai was making was in reference to when you said this: "you can't make a game built for casuals appeal to the competitive crowd." Which is simply completely wrong.
Magic: The Gathering started as a small, pretty casual card game and is now immensely popular with world-wide tournaments and world championships.
SSB, SSBM, SSBB were all designed and made to appeal to the casual crowd (Nintendo has actually fought against the competitive Smash scene) yet SSBM/SSBB have thriving competitive scenes that rival even SC 2. (You could probably argue that the competitive scenes of Smash are better and even more relevant to e-sports than SC 2 currently.)
Hearthstone was also made aimed entirely at casuals yet consistently gets 30,000+ viewers on Twitch daily, has international tournaments, is being featured at huge multi-game LAN tournaments etc etc. I don't see how you can say it isn't relevant because it has no micro or macro. Chess has no micro or macro and is still an extremely competitive game. A game doesn't need micro/macro to be a good competitive game.
DoTA 2 (which obviously spawned LoL [and DoTA/LoL are probably the largest e-sports we've ever had]) started... guess what... as a COMPLETELY casual game for killing time between WC3 ladder matches. (Yes the idea of MOBAs goes back to SC1, but none were even near the same level as DoTA/LoL are)
So let's recap. The two most popular esports ever started as completely casual games. One of the most popular fighting games ever started as a casual game. The two most popular card games (MTG/HS) both started as casual games. Even SC:BW, which is probably the most competitive/skill-based RTS of all time, was NEVER designed to be competitive.
So yes, you absolutely CAN make games designed for casuals turn into highly competitive games. SSBM is more relevant to e-sports than every RTS except for SC:BW/SC2/WC3. Hearthstone is more relevant to e-sports than even SC 2 is currently.