Though the EV will be positive up to a certain level when playing at these competitions, players may not be able to take advantage of this because:
1. They did not come to know about it.
2. They are not good in evaluating whether the EV is positive or not, and whether it is a good idea to (at least in theory).
3. They do not have the bankroll to.
Mission : Rank 3 on magicaldice competition. Prize : 1BTC
Didn't you just make the point 1 and 2 invalid with this post, and as a result make it harder for you (and those bankrolling you) to actually win the prize by attracting more competitors lol?