That's a good analogy, and I can admit that I saw a video of PBE Quinn and thought--that can work.
Yet, in all fairness, she doesn't have 133% speed all the time and while she can gank, she's not an effective ganker.
She's good at burst, and I can't say that, that's a negative thing. Yet to be fair to all Quinn mains, she already had the ability to gank, burst and on top of that duel.
Now, while she can technically gank and burst, she can't duel and that's one of the major problems to me (and I suspect most people).
Every other champ, regardless of theme, has an escape mechanic, a chase mechanic and a dueling mechanic.
Caitlyn is a sniper theme; but she sets traps to duel effectively and she shoots a net out to escape, and she has her ult to chase.
Vayne is a hunter theme; but she can invis to 'escape', she has big movement speed to chase and she does 12% true damage to duel.
Graves is a shotgun theme; he can escape with a dash, chase with a dash, and he can obscure vision.
You get the picture.
And this isn't all to be thematic, but more so to be functional in a MOBA where there is a constant threat of ganks and maneuvering and out maneuvering.
The TF2 Scout a an FPS character, not a MOBA character. I.e. a FPS Sniper may set traps, but being blown away by a net gun (Caitlyn) isn't remotely thematic.
Obviously, Quinn has huge movement speed boosts (W) regardless of her Ult; but unable to duel with it the Ult but to burst, makes her lackluster compared to other champs which can escape, dash and duel.
If Riot really wanted to go with the Burst theme, they could have made w and her ult proc her passive. Also, as q should apply a debuff, they could have made it increase her damage and/or decrease her enemies damage. It's not a blind, but it's also not useless in a duel.
For now, we can just think of other burst ADCs and ask ourselves which is better. Quinn who can get into a good position fast and do nothing, or others who may be in poor positions but do a lot there.
ALSO: If they wanted her to do more burst--why remove the damage and execute off of skystrike her ult?