I actually disagree. Even a lv 0 opponent should be at least theoratically able to beat something. I've seen small decks that are completely impossible to lose against, so it's not even fun to duel them... They are supposed to be easy, yes, but if you can't lose against them you might just as well be given money...
It's not the purpose of this opponents that you like beating them up. As Zanz said already, they are for newbies to battle their first one or their first two duels. Newbies which may not even now the conzept of Quanta (or donยดt even now mana from magic) so they are completely clueless of what is even happening. They may not know that there are different card types, or whatever.
So like in most games, these tutorial-sandbags shouldn't be able to give you a hard time, even if you draw no card that can damage the opponent or his creatures for the first four or five turns. (Which might actually happen if you fight with the fire starter deck. And even after ten turns you may have only drawn one single ash eater)
But actually, it's not even useful talking to you guys, since you don't need to like (or fight) them anyway. (And about "free money" from them because they can't win against you: you get 2
for fighting them for 1 minute, 120
per hour if you hurry up, if you think about winning cards as well, it may be about 250 coins if you sell them (no rares, and mostly "weak" cards from winning), for an hour of really boring grinding.)
Putting everything what i stated aside, i too think that some of the weak decks need some extra cards to stop them from decking out to early. (Because that is something that should ABSOLUTELY NOT happen to a newbie in the middle of his first fight.) (they shouldnยดt be stronger, just have some extra cards to last at least 15 turns (24 cards))