The "very developers themselves"? You mean Team5? Talk about an unreliable source. I played Hearthstone for years, and I visited the forums. I know exactly how unreliable they are, and how the community feels about their design decisions by and large.

You claimed that what you posted was "proof", but you didn't prove anything. You just made an assertion. This community - the one that matters, the one discussion Eternal - seems to disagree with you. That should be enough.

One more thing, since you seem like one of those "fallacy! cognitive bias!" people - just because an argument contains a fallacy, that does not mean the argument is invalid. Sometimes, argumentum ad populum, ad hominem, to quoque, and the like are exactly what an argument needs to reach the truth. That is the case here. There is no "official definition" of interactivity in Eternal or MTG. So we go by the common understanding thereof. The one that the majority of the community uses. So call it out as a fallacy if you want, but that's how these things work.