If you going to risk 10btc to make only 2 it seems too risky. Rather risk 10btc St 50% or 2 BTC at 50% then you accept the loss and get 8 BTC or win and have 12bfc. Having 8 left is better then having 0 left.
It is hard to say whether players would be risking 10 BTC at 80% win chance to get a 1.2x payout win because I have seen some players using this strategy and they did really manage to get some profit from this method. but this method doesn't suit my style as I feel the payout is way too low and if I lost just a couple of bets, It would be really scary to start chasing the losses back.
You must be too unlucky to lose twice or three time with 80% chance at first bets you make. On long term surely this consecutive loss streak comes, but for the first bets it's very hard to happen. All you need to do is to win once with these configurations, one bet win is sufficient to make a big profit and enjoy it. Some gamblers like to do the inverse, lower chances to win, but bigger reward multiplier.
You can even loss the first time. What if you lose the first time ? You think it won't open untill only the second or third but if it happens the first time it will hurt.