The real problem with "win-more" cards is that they're conditional. Being conditionally good is a common criticism of many magic cards. The advice to new players is simple: think about how likely these conditions are to be met. If they can't make this estimate, copy a more experienced player's opinion.

It's also possible that a "win-more" card is also just a decent card even when you're not winning. For example, if you play MTG now, you'll know that 2 desecration demons on the play against G/R monsters is both very good, and that the second demon is "win more".

So I don't really see a problem with playing "win more" cards. The problem is playing too many conditional cards.