I'm not gonna rag on your definition of fun - if you enjoy the brokenness of buff beams, more power to you. But as for me, I take enjoyment in my choice of what towers, heroes, abilities, and pets I use to beat waves. Introducing a copy of DD1's buff beam removes that choice, because the game has already picked for me. The balance of the game dictates that I use it in every map, or else I'm severely gimping myself and making the game much more difficult than it needs to be. This is the importance of balance - it allows players to pick their favorite ways to defend without making the game unnecessarily difficult. Pets, heroes, and their abilities can be tweaked to be properly balanced. Buff beams acting as a multiplier that scales with stats, no matter how they're tweaked, cannot be properly balanced.
Don't bring over the summoner because:
If I want the DD1 summoner experience I can just play DD1
I would rather those development resources be dedicated to a new and unique hero, and not a rehashed one that everyone has already played
Introducing the summoner is yet further proof that DDA is just a copy of DD1 (as if it needs more proof lol)
If minion units are a thing, then that further boxes players into a single type of gameplay, especially if buff beams in their current state are released
While an RTS in a tower defense game is a pretty novel and interesting concept, is not the most efficient way to play that hero. Instead, effectively doubling your defense units with minions and plopping them on the broken buff beams we're talking about here is the most effective way. Doubling your DU with minions, once again, removes the choice of building.
I digress though, as the summoner in DDA is not confirmed. I don't plan to bring it up until a) it's announced; and b) we have an opportunity to see how it plays, and specifically if the hero uses MU or not.