This page contains the reasoning behind the KirriCorp League's errata on the card Bombazar, Dragon of Destiny, shown below in its original form.

Name: Bombazar, Dragon of Destiny
Type: Creature
Race: Armored Dragon/Earth Dragon
Civilization: Fire/Nature
Cost: 7
Rules Text: [Double breaker]. [Speed attacker]. When you put this creature into the battle zone, destroy all other creatures that have 6000 power. Take an extra turn after this one. You lose the game at the end of that turn.
Power: 6000
Mana Number: 1
Set: Shockwaves of the Shattered Rainbow

As with all KC errata, justification of this argument relies on the semi-rigid card costing system given within Duel Masters. The relevant aspects of the cost system are shown, with examples, in the following data. No direct assumptions are made about the cost of a card that causes other cards to be discarded.

Ability: To take another turn.
Cost: Unknown.
Reference: Balesk Baj, The Timeburner

One would wonder why this would even be mentioned, if the cost is unknown, but this is precisely why it is mentioned. What cost would a 1000 power creature with the battle zone entry ability 'take another turn after this one' have? Such a creature does not exist. Rather than reason that this card's cost is wrong, we will instead have to reason why the card 'does not exist'.

If we assume that such an ability costs at least 8000 power, then a 7/1000 creature should be able to have it. This creates the situation where getting to 7 mana would presumably allow one to attack with every creature on one's field, twice.

Whilst extremely annoying to those with either no blockers or insufficient blockers (since you could only block once with each) this would not be considered outright unfair by most, and in fact might be discarded as too silly and unreliable.

Eventually, someone would find a way to combine it with Aeropica or King Neptas and become really annoying, sucking a lot of the fun out of dueling them, since they would be able to keep this up until they had enough mana or hand to just plainly win.

Clearly, then, regardless of all else, a further condition must be applied to such a card. A penalty or restriction to prevent Aeropica from making it close to unstoppable (considering that one never has to attack and even risk triggering discard trigger, one could simply use the time to rise to large amounts of mana and summon Bolmeteus to do that).

Balesk Baj is required to make an unblocked attack, and is furthermore required to return to hand every turn. Bombazar is restricted differently. Only a single extra turn is granted. Then you lose. Clearly, this is pointless if you cannot finish the opponent in two turns. If you can manage this with any great chance, then a Twin-Cannon Skyterror could do almost as well.

Almost.

The opposing ability to counter Bombazar relies almost totally on two things. They must either have blockers, enough of which to stop the entire assault, or shield triggers, preferably a Holy Awe on that 'second turn'.

The argument that 'it is unfair to players who have no blockers' does not hold weight in itself, because Balesk is just as dangerous to those players, even considering that it is an Evolution with a cost of nine. So clearly the problem must lie somewhere between the card itself and the mechanics thereof.

It is clearly defined in the simple realization that Bombazar is the easiest possible terminating card, requiring no effort to set up beyond having the correct mana to summon it, and one other creature, assuming no opposing blockers. It is considered unreasonable to require players to instantly destroy/prepare to block every single opposing creature even if they have five shields at the time.

The Bombazar player is in no way required to summon the creature until the situation is at least mildly favorable to them. The issue lies in the vast number of situations that can be considered even mildly favorable. Therefore, though the card can be stopped, and its weakness exploited to gain victories, it is considered to be an unreasonable addition to an otherwise reasonable game system.

Update!: The Errata Rules of the Dragon Of Destiny have been decided upon, courtesy of Nerafim!

Name: Bombazar, Dragon of Destiny
Type: Creature
Race: Armored Dragon/Earth Dragon
Civilization: Fire/Nature
Cost: 7
Rules Text: [Double Breaker] [Speed Attacker] This creature can't be blocked by any creature that has power 5000 or less.
Power: 6000
Mana Number: 1
Set: Shockwaves of the Shattered Rainbow