It doesn't have to be all or nothing. The proper strategy would be to sell a percentage at $10.
In fact, if you started in 2011 with 1000 BTC and every year you sold 50% then today you'd have (by my rough calculations):
8 BTC (worth about $50k)
$160k USD
Of course it's not the millions you'd have if you just held each time, but for many that is a life changing amount of money and you would have obtained it in a responsible manner that doesn't just rely on the value of Bitcoin shooting to the moon.
In fact, if you started in 2011 with 1000 BTC and every year you sold 50% then today you'd have (by my rough calculations):
8 BTC (worth about $50k)
$160k USD
Of course it's not the millions you'd have if you just held each time, but for many that is a life changing amount of money and you would have obtained it in a responsible manner that doesn't just rely on the value of Bitcoin shooting to the moon.