In Magic: the Gathering, both players start with 7 cards. The player who goes first skips his or her draw phase, i.e. the second player plays each turn with one extra card in hand. This balances the drawback of going second a bit, but generally not enough, and virtually everyone chooses to play first if given the option.
Hearthstone adopts the same mechanic with one extra wrinkle: the player going second starts with a "Coin", which is effectively a
Lotus Petal. The games are more balanced in Hearthstone as a result - as far as I know, play/draw in Hearthstone has negligible impact on win rates.
Is there any reason for Magic: the Gathering not to adopt the same rule (i.e. player going second starts with a Lotus Petal)? I know Magic is a more complex game, so this could potentially lead to something degenerate. However I am not sure what. The only thing I can think of is that a player going second in Legacy or Vintage is now more likely to storm combo off on turn 1; however because he is still going second, the opponent would be able to cast
Thoughtseize or
Spell Pierce first. Besides, the opponent is still going first: his
Counterspell comes online quicker, he can play
Liliana of the Veil before the opponent can play 3-mana spells, and so on.