Not like Stein's the only card whose status differs between Duel Links and the TCG/OCG (Grass and Gold Sarcophagus for instance.) Different cards are stronger in different formats, and for different reasons. Pointing out a card's status in one has no bearing on what is warranted in another.
Rekindling would be DUMBER here than in the TCG. Sure, the raw combo potential is lower because we only have 3 monster zones. But Summoning 3 2000+ beatsticks (especially the two Hazy Flames) is obviously not acceptable.