Because, yes... Music industry and digital recordings produce many vocal anorexic singers. When I am talking about anorexia vocalis, I am talking about the wish of every young singer: to sound like the big names on the recordings they hear when they are listening to CDs, tracks on Spotify, and so on... You wouldn't believe how damaging these digitally remastered and studio-steril recordings can be. But it's not the fault of studio workers, I wouldn't put the blame on them: they are just doing their job, though they assist in spreading the disease. No, no... The real suspect is the insane guy who came up with the idea of well temperament. I'm sure he just wanted to give a stable and easy system that would help musicians to find their way in the dark forest of tunings, and his intention was pure, I'm sure about that. Also, in the very beginning "well tempered" meant that the twelve notes per octave of the standard keyboard are tuned in such a way that it is possible to play music in most major or minor keys and it will not sound perceptibly out of tune.You see? People didn't play out of tune before the well temperation, it just sounded perceptibly out of tune.(Side note: I don't mean to rip on classical trained musicians, but meantone, pythagorian and other early music tunings don't equal with "playing out of tune"...). And on the other hand, this system suggests that there are no notes between E' and F': true, there is almost none for an instrumentalist (especially on a keyboard), but I assure you, there are plenty of notes between those two for a singer.
Intonation and how tuning works depends on several factor. It depends on the architecture of the building where you are singing. For example if you have ever sung in a Gothic church, or anything like that (like the Chapel at Fontys Conservatorium in Tilburg), I bet you've realized that the architecture pulls up the sound, and even if your intonation is flat, the architecture will pull it up (along with everything else) for you, while Roman churches are pushing down on your voice a little. Composers before the time of well-temperament were aware of this element, so they took it in account when they were composing a new piece (for example organum will never sound as marvelous in a Roman church as it does in Gothic cathedrals).
Another factor is the breathing: if the singer doesn't have a natural and healthy airflow, the lack of it will lead to intonational problems. If you are pushing the air instead of letting it flow, your intonation will be flat, and you cannot get into your resonance or at least you'll have some difficulties with it.
I know great singers, whom are considered having bad intonation, though they have excellent ears. They are constantly fighting with the negative feedback of exam committees and senseless concert venue directors (who - for some really weird reason - think that they know everything about singing... ridiculous...): they are told that they should develop a better intonation, but these "clever" people have no freakin' idea, that their feedback doesn't help the singer.
I suffered from anorexia vocalis as well until I figured out, that studio recordings are studio recordings, and "clever" people are not as clever as they think they are. Cleaning up the sound on a studio recording is like photoshopping a pizza into a woman. If you think it's not possible, just check the video below
I'm not saying that everyone sings like a pizza and then they are going to make a studio recording and they become a hot chic. Nope... I'm just saying that even the most excellent singers have bad days and they also sing out of tune every once in a while. I agree with Andrea von Ramm, that a concert where every single not is well in tune is a boring concert. Please, dear performer, make a mistake for me! Prove me that you are a human being like I am and you don't thing that perfect intonation rules above all. I'm interested in your talent not your perfect intonation.
