So, on the one hand you have Lana Del Rey. Physically flesh and blood, with all the things that that entails. But at the same time she can be considered to be manufactured because she has the money and resources to adopt whatever trappings she needs to appeal to a specific audience, in this case that of alternative rock. The problem with that is that one of the things valued by most types of rock fans is a sense of genuineness. I know I certainly did when I first started venturing out and listening to my own music for the first time: while I could appreciate that the manufactured pop music you heard on the radio sometimes sounded nice, there wasn't much to it beyond that. Rock music catered to all the complicated emotions that pop music preferred to avoid, and I liked it that way. When you get manufactured rock or alternative music, it can seem like it's kind of missing the point. Lana Del Rey might be a fantastic songwriter and musician, but if she's only superficially adopting the trappings of a subculture, then it seems very cold and calculated and thus completely out of place in the genre. I remember there was a similar reaction to pop-punk bands like All Time Low and their ilk when I was in high school and college. My reaction was largely the same now as it was back then: if you don't like the music or the band, for whatever reason, then don't listen to them. Additionally, don't expect me or others to conform and agree with you, even if I do understand your reasoning. For instance, I couldn't stand the band Gallows, because they just weren't to my taste and the vocalist came across as a thoroughly unpleasant person, but I had largely forgotten they existed because I have better things to do than moan about music these days. In any case, not being a Lana Del Rey fan, or even an ex-fan, I couldn't really attest to the genuineness, or lack of, in her music.
On the other hand, you have Hatsune Miku, and by extension the other Vocaloids. Not physically real, boiling down to the manipulation of pitch and phonemes. But I would argue that despite being not technically real, you cannot really say that Hatsune Miku isn't genuine in its intent, simply because her fanbase has the opportunity to add to her musical output. While it's almost inevitable that a portion of the music that is made using her voice will be indistinguishable from the manufactured pop music made with human musicians, the fact that the software is available to anyone who wants to use it and is only limited to the skill of any one producer makes for a potentially vast variety of results. With Hatsune Miku one only has to compare Gift from the Princess who Brought Sleep to World is Mine to prove this: one "voice" producing two songs that are totally unlike one another. This variety and potential for close involvement with the fan community is what prevents Hatsune Miku and other Vocaloids from ever becoming wholly manufactured, as there will always be one producer who wants to use them as tools in a wholly different way.