Considering Sekac is completely unproven I don't think anyone alive thinks 12 Sekacs is a good idea.
But neither is playing Moen, Prust, and Weise at the same time. Especially when you also have Malhotra (not much offense) and Bourque (in theory offense, but a below average possession player out there. That's not a good bottom 6 on paper or in reality.
The problem with players like Prust is they have a limited shelf life, and become Moens. Moen still can play, but he can't move fast enough to play overly physical, and was never a good offensive player to begin with. Prust probably has the most heart of anyone on this team and his willingness to stand up to anyone makes him more valuable than his play, but he's degrading as a player and that is significant. He shouldn't be playing more than 10 minutes most nights and he definitely shouldn't be off the 4th line. He probably shouldn't be playing every night if we actually want him to be physical and not die out there in fact.
People want to see Sekac and Bournival because they can get better, while Moen is only going to get worse. And quite frankly Bournival has a long way to go when it comes to offensive upside, so if Sekac is overrated, it's because he's our best hope at preventing our 3rd line from being an offensive black hole.
Eller isn't the problem, sorry. The mythical third liner who can make Bourque and Weise a good supporting cast doesn't exist, because that isn't anything close to a third liner.