You didn't read your own source. This article does NOT say the Martingale system has +EV.
First, it says the EV is zero in the case of infinite funds for the coin flipping scenario, i.e. when the bettor's probability of winning is 0.5.
We're talking about roulette, where the bettor's probability of winning a single bet is less than 0.5, and where the EV of a single bet is zero. In that case, the Martingale system is always -EV, even with unlimited funds.
The key passage in the article that applies to the Martingale system is:
Thus, for all games where a gambler is more likely to lose than to win any given bet, that gambler is expected to lose money, on average, each round. Increasing the size of wager for each round per the martingale system only serves to increase the average loss.
This is true no matter how many rounds you add up.
If you think the system is +EV, let's see your math.
BTW, I'd be willing to bet you a large amount of money that you're wrong.