For me it depends on situations and the situations inside situations:
Situation 1: Human (nonsynth) Vocalists
subsituation1: Correcting Vocals-> It is okay to use, it is commercially viable, sounds good, etc etc. Everyone uses it after all...
Subsituation 2: Using as playback on live performances: not very cool...Unless you have something to compensate it (very exhaustive dance moves for example) that is not a cool thing...people paid for the live, they will likely want at least live vocals, right? Effort...
Subsituation3: TPain effect-> I love it...on certain genres, certain song moments, etc.
Situation #2: Vocal Synths
Subsituation 1: Vocal Correction (???): Well, actually there is not much vocal correction to do on a Synth since they are already autotuners on their own way: UTAU, for example, takes a D4 sample and play and adapt to a G4...Unless the tuner mess with modulation or pitchbends the vocal will already be "autotuned". I dont think it is very cool, but it is not really bad either.
Subsituation 2: Using it on everywork of yours independent of muaicak genre: After VOCALOID4 was released, tons of people made covers and all of them...Used the pitchsnap/autotune feature of V4. No one bothered with tuning, or if the autotune matched the genre...That was meh, vonsidering another considerable number of VOcaloid tuners also came with V4 and their work, initially, was overshadowed by AutoTuned Miku covers.
Subsituation 3: Effects-> again cool to use when it matches the genre