Maybe but if playing it without those aspects makes you level up faster, be a better teammate etc instead of just dodging enemies and incoming fire [looks to me all its good for] then people are going to disregard them.
Your'e right.
SMART won't help you get around, over, under and through obstacles that get between you and your objectives.
And you won't be able to get in close to a teammate while evading fire just because you know how to wallhop into paths the Heavy can't follow you into.
/sarcasm.
There's more use for SMART than just "dodging" - and even dodging will have its objective-based uses. Skilled players using LIght bodies and effective SMART-based play will be quite capable of getting to objectives MUCH faster than the defenders expect. They'll also be able to find paths which other body types, or less skilled players, would never reach, and as such, would never suspect.
Also, there's the novelty value which makes some videos worth doing - find places you can do multiple wallhops, just to film from another player's perspective and watch a guy bouncing between walls somewhere just because it looks cool - even if it's totally impractical in any realistic sense.