Okay, it looks like you desperately need someone to side with you seriously. And since I've been in your position before, I'll do my best.
The Green-Grab Function
This is the trademark element of Scout. It can siphon off as many as four victory cards, which are often useless other than their point values, paving the way for your key draw cards to get at the good stuff. In most decks, this effect doesn't make much of a difference, since, for example, a well-constructed engine draws past the green without much effort, or a slog deck doesn't mind having low-income turns anyway. By the time most decks are clogging themselves with green cards, it's too late for Scout to matter. But there are a few times when green-grabbing can get you places you want. Most obviously, with a deck heavy in functional alt-VP, a Scout can get up to that sweet, sweet double-Lab effect. Silk road works too. With a spare buy or two in an Apothecary deck, it can helpfully avoid that nasty pile of victory cards left when you pull all the coppers out from in between them. And then there's the counter to things like Rabble or Bureaucrat, where it can sift right past the attack and get your deck running again.
The Deck Inspection Function
Although it doesn't give the benefits of something like Cartographer, Scout does give you advance knowledge of up to four cards. This gives it great synergy with cards like Wishing Well and Mystic, and also their cousins like Vagrant and Magpie which depend on a certain type of card being there. Even if there's no card that directly benefits from deck inspection, an extra Scout could give you an insight into whether it's worth it to play that big terminal draw card with your last action or not.
The Non-Terminality
Hey, it doesn't waste an action to play it! In this respect, it's vastly superior to other "useless" cards such as Chancellor or Duchess. (I actually made a kingdom with the two lowest-rated cards from each coin price category - Scout was the only non-terminal on the board.) This can lead to some interesting considerations on boards when it's the only non-terminal. Prince it, and you have a permanent village. Have Golem hit it, similar story. And unlike Ruined Village, there's something it does besides give you another action. Speaking as someone who's directly benefited from a Princed Scout, it feels good when you can get that extra action in play and know what's coming next.
The Opportunity Cost
All of this ignores the downside of Scout - it takes four coins and a buy just to stick one in your deck, and even then there's no guarantee you'll draw it at the right time. Sure, outside of a big money deck (with dead-draw tendency) it might pass the silver test, but it rarely passes the other-cards-on-the-board-at-similar-prices test. I'd much rather spend a $4 hand on a Village, or a Vagrant, or a Conspirator, or a Sage, or... the list goes on. There are very few times when a Scout would be essential to someone's deck, no matter how helpful it might be otherwise. This is why it's a card that is often reserved for spare $4 buys, which don't often happen. The strategies that really take advantage of the three functions I mentioned earlier are the exceptions, and even then the nature of a game might not allow time to get enough Scouts to make a difference.
Edit: How the heck could I forget gainers? In games with Ironworks or Workshop or something, Scouts get a lot closer to free, so the opportunity cost can get low enough for you to get the small (sometimes not so small) help that Scout gives without having to pass up something more essential. I agree that if the only important pile of $2-4 actions runs out in an engine game with Ironworks and no victory chips, some Scouts should DEFINITELY leave the pile.
So like, Scout doesn't deserve as bad a rep as it gets, but it needs a bit more power behind it to be relevant enough to shake that reputation.