For me, art and descriptions are the last thing I look at. I know what a dwarf is, I don't need it described to me. But the stats do matter in game and they set a baseline of expectation. I do get how art and descriptions can inspire people about a race, especially for new players, so I can certainly understand the frustration PS fans have.
I see very little complaint about the mechanical stats of tiefling, so I color that a plus (I could care less about tiefling, any edition, not my cup o tea), and I think they stats are fine. Cha is a bit odd (Tiefling Bards seems odd given the fluff they present...well on second thought, maybe Tiefling bards are Goth/Emo/Punk...lol!)
Artwork: Yup, that is a tiefling. It may not be your vision of one, but its not subtle, and I think that's important for art in a game book. A subtle PS tiefling might not leap out and scream "TIEFLING". My biggest headache with Star Trek (which I love) is the ubiquitous human-looking people with small distinguishing features to tell you "not human". I am glad for a BOLD tiefling (even if the horns are usually over-sized).
I would like some more sub-races of tiefling (planetouched), but I think something has to give...everything can't be in the PHB. Likely there is a priority at play here:
Elves/Dwarfs/Humans/Halflings are obvious 1st priority with many sub-races
Tiefling/Dragonborn fit 2nd tier
Warforged, Minotaur 3rd
Monsterous races4th
1st tier gets full PHB treatment
2nd tier gets minimum PHB with either variant sidebar for sub-race or DMG work-up for sub-race
3rd tier gets minimum treatment in DMG
4th tier gets a sidebar, mention in MM
IMO, of course