I think the question would feel better if it at least laid down a baseline of what is being judged. Engines are toolsets, and those toolsets are good or bad from a developer's perspective depending on a set of criteria that no outside observer (i.e. 90% of consumers) is going to understand.



Now if we want to judge which engines have produced consistently high-performing games with impressive results, how much of that can be put down to the engine, rather than the unique optimizations that every modern production has to introduce to make it run on the targeted hardware?



Without a sensible guideline this conversation risks just being 'this game performed poorly therefore the engine is to blame' for a while.