Well, yeah. Utility is generally anything not damage-related. It's a broad category. Again, it's why Ashe is a "utility carry" - she packs a very large amount of solid utility with moderate damage. They wouldn't call her that if they were only referring to the utility of her E. That's one single vision-granting ability - that hardly justifies a utility carry. Quinn does a very similar thing on a lower cooldown, and she doesn't qualify as a utility carry.
And that's not the attributes of champs you look at. You have three main categories - utility, bulk, and damage. From there, your utility is crowd control, buffs, debuffs, sustain (meaning healing and shielding), passive penetration (such as the armor pen on Gangplank's barrels), your mobility, and some miscellaneous things such as Anivia and Azir's walls or Eve's and Twitch's invisibility; bulk refers solely to how much damage a champ can soak up, with Galio and Rammus being your special cases; and damage is damage, but is broken down into burst and sustained (for example, Azir is largely sustained versus Veigar packing burst).
So to sum up Vayne: Vayne is a very high sustained-damage (or DPS) champ with a stifling amount of utility at her disposal and minimal bulk. Generally, though, a lot of ADC's have a lot of utility relating to mobility at their disposal (snares, slows, or leaps). Hardcore disables (like stuns or blinds) are only seen on Vayne, Teemo, and Urgot - and two of those are only marksmen in the strictest terms, with one of those two normally not building AD anyhow.
So backtracking to the original point - you're hardly focusing on the point, which is that Vayne has a stifling form of crowd control that's easier to land than people care to admit and should be balanced out.