I value creative insight in fields that involve analysis of creative work mythology, art, and literature.) Academic scholarship is important, no doubt, but neither is it the entire picture.
Although Graves was not assigned material when I was at University, neither was reading him discouraged. Although his material may not be cited in academic literature, he was held in high regard by many scholars personally.
Graves Translations: I find the value of The Greek Myths to be in the way Graves compresses all of the different versions of the stories into a single narrative. (This may be what some believe to be "not faithful"). He cites all of his sources, thus the actual texts can be utilized for scholarship purposes. (This is how I use Graves--his index is incredibly robust. It's generally my first stop running down source material, and definitely more reliable than non-peer reviewed internet sources.) The prose has great literary merit.
Graves' Analysis: It was largely based on Frazer and Jung, and although these schools of thought have rightly diminished as the academic field has advanced, their ideas and contributions are nevertheless important. (Frazer was a trailblazer, and Jung is useful from the standpoint of symbolic logic.) Although Graves analysis is very interesting, I don't use it for scholarly analysis. The lasting value is that many of the most significant literary artists of the 20th century were also influence by Frazer, and these artists, (Yeats and TS Eliot, for instance) also commented on mythology in their poetry, plays and prose. The stature of such artists is immense, and places them in the tradition alongside the great poets of antiquity, although this is understood as the Literary Canon as opposed to the Mythological Canon. Nevertheless, The Golden Bough is itself a mythology, and will always be relevant in that it assists in understanding proper poets and storytellers who were influence in it.
Name Meanings: I was speaking to a Professor of Linguistics recently who pointed out that in instances where we don't have textual confirmation of a name meaning, everyone, including scholars, are guessing. This is an area where I might consider Graves' insights to be most valuable--he was a poet and novelist, thus his business may be said to be "profound insights". (i.e. any creator worth their salt has discarded more insights than they have used, by orders of magnitude.)
For Classical Scholarship: Use Graves only to get an overview of the source material and to run down sources. Do not use his commentary, but value his index.
For Art: Graves can be incredibly valuable for artists and creators, because his commentary is fruitful ground for the imagination, and useful for generating insights about modern literature. His commentary may be taken as a form of non-canonical mythology from a very fine and serious literary artist.
For some context, compare Pope's version of Homer to modern translators such as Lattimore. Fidelity to the actual grammar and vocabulary is a fairly new development, and well wielded by modern translators, but was not the standard to be aspired to until perhaps Lattimore.
When it comes to translation, Lattimore is my guide, greatly revered. But when it comes to creative insight, Graves lights the path.
Also of interest: The White Goddess