Because it became saddled with SJWism and PC culture.
That totally makes sense. The original Star Trek, of course, was completely unconcerned with issues like race relations, social justice, equality, multiculturalism, and all that other socialist garbage. If only we could go back to those long-ago days of the 1960s when nobody ever talked about these terrible newfangled hippie-dippie ideals!
I think 2017 is not the 1960's - and the problem is 'populist social leftism' is still using the 1960's playbook.
It's tired, it lacks nuance. The new Star Trek's remind me of the Canadian government's 'soft propaganda' in 'Degrassi Street' - which is lampooned spectacularly well on 'Kroll Show'. And I don't use the term 'propaganda' lightly - it's state sponsored 'youth education' - again, which can be positive, but it's always going to be a hint 'North Korea' no matter how you cut it.
I think motives are not so bad ... but we live in a new world. It's not so easy as 'putting a traditionally marginalized person in a leading role' anymore. That's all fine, but it's not thoughtful. It's Disney. And lazy.
As evidence of this culture - here you have a show that puts extraordinary attention on putting 'marginalized people into leading roles' - and yet the storyline is 'still racist'. This is getting ridiculous.
How about 'it's just not good'. Because it's not?
Coen Brothers said it right - while 'diversity might be important' - the most important thing is the story'. Start with the story, focus on the story. If you start with a social objective, it's just going to come out all wrong, and be 'bad'. Like the new Star Trek. Sadly.
"If only we could go back to those long-ago days of the 1960s when nobody ever talked about these terrible newfangled hippie-dippie ideals!"
It's not a 'hippie dippy idea' in 2017 to have a 'Black Woman' in charge of something. It's not common, but nobody will bat an eye, and I really don't think the vast, vast majority of people care one way or another. It's not the 1960's.
There are a lot of interesting stories to tell, that may very well involve 'non classical' views, so let's tell them.