I think the only Meren decks that don't want multiples of that effect is if they are building a very high powered list, where this kind of play 'isn't advancing your board' sufficiently
You'll find the full developer post over at the official website, but if you're looking for the short version, here's a couple of choice quotes: "To affirm what we talked about back in September, a smarter system that provides what we have dubbed "duplicate protection" is still our top contender, and the current design space we're working with." "Okay, so we have the goals we want to accomplish, we have the problem space, and we have a system that will help us reach these goals
In other words, it is now the premier manland
With Eternal Dominion, survival depends cards in other decks
This deck used to be an unconventional choice in Modern, but its proven that it has the strength to be a real player in the right metagame