If you watch the complete video, you are shown that you can do exactly what happens with the keypresses, by way of using a castsequence macro (at about 6m50s), so the end result is effectively the same by using the in game macro system.

Also, anyone can mash multiple keys on their keyboard, so it's not like you need special software for that. It's just that instead of mashing 3 keys, you just hit one. People can also setup their gamer keyboards to do that too, so again, not something which is excluded from the masses and proving an unfair advantage (there are probably still people that would whinge about how they can't afford that either so its unfair, but then they might as well complain that they don't get the fancy graphical effects on their Hercules CGA card too).