In doa you have to guess constantly all the time. It's a system where, in most cases, the least safe option for a player is to attack, and nothing is guaranteed. The attacker doesn't get properly rewarded for putting their opponent in a bad situation, because they're always at risk of taking as much or even more damage than they could dish out. That's about it. It's not a complex issue.
You can say what you want about doa being doa and all that, but the fact is that doa has never been a competitive game and even competitive doa players want the systems to change.