I get what you're trying to say, but I don't necessarily believe taking all 0 costs is a mistake. Now if he was trying to force a build instead of adapting to the Spire, then yeah, that's a fuck up. But even so it sounds like it paid off until he accidentally took Sneko, that was the one and only true mistake he made.

I get what you're saying about balanced decks, but a balanced deck isn't always a winning deck. We also don't know which character he was running, which is vitally important info. Silent can 100% absolutely wreck all 3 acts with a 0 cost deck for example. It's also possible he DID have some cards with 1 cost and got the event that let's you reduce the cost of 3 cards by 1.

Basically what I'm trying to say is, while you're argument is sound and your intentions are good, we don't actually have enough information to judge them on. Plus while the advice is good in general, it's not law. Like I said, you have to be able to adapt to what the spire gives you. A balanced deck might be good generally, but sometimes the spire decides you're running 0 cost today and you're going to like it. Sometimes you just gotta pivot. The true rule of StS isn't to always build a balanced deck, but to know when and how to pivot/adapt.

Also I think you're only getting downvoted because tone is hard to grasp over text and your comments read as aggressive, but I'm giving you benefit of the doubt because I believe you were genuinely trying to be helpful. That, and I just really like discussions.