As for Jaron, and his massive wall of text, his words might have some merit had he not honestly claimed, on many occasions that playing enemies remotely intelligently or competently is worth large CR boosts. Since he has, all he's proven is that he can beat other mouth breathing fuckwits.
I've never claimed this. I have had that the encounter level of an encounter (which, in the case of monsters, is effectively the same as CR) is altered by giving the creature significant abilities above and beyond what the stock creature has (like Mindsight) and by giving the creature information it shouldn't have (like enough to create an ambush). I have consistently said that creatures should behave intelligently within the bounds of what they know. This is why I said the CR goes up when you customize the feats to be much stronger and let the creature know more than it should, but then criticized you for playing that creature so stupidly once you had given it that info. Read the DMG for more information on this.
Remember, the normal CR guidelines assume a standard encounter start (you and the monster somehow get within range of each other and spot each other) and standard feats/HD/skills. The more you give to the monster, the higher the overall Encounter Level. But once the EL is set, you should play the monster appropriately... an Int 22 monster who can see through walls but knows enough about the party to know about the Cleric having Lifesense should obvious bury himself in the snow so he's hidden from that sense but can still see. So yes, the encounter you've set up as proof of how scouts suck was one where A) scouts would actually be very useful and B) the scout is defeating a level +5 (at least) encounter.
What I suspect is really going on here is you haven't actually played NEARLY as much as you claim, that these "+30 to hit" Warblades you speak of only happen within the specific campaign rules you've set up (if they happen at all and you're not just mouthing off because you want to sound smart), and you don't ever actually play by the game rules as written. As such, your general claims about how the game is played are completely irrelevant. And you've clearly never seen a player playing a scout appropriately, or you'd never have made stupid claims about splitting the party (or freaked out about Darkvision as though that weren't easily counterable).
In the end, you're just a guy who's never seen it done and assumes it can't be done as a result. This is all Theory and Dragons, not Dungeons and Dragons. Well, you're talking to people who've done it for real just fine, and against very intelligent enemies who actually use the resources they have to hit rather hard. Sit back and read, you might yet learn something.
JaronK