tenure track fashion
The problem is that so far it borders on unscientific. The expressed attitude that whatever the astronomers observe, either A or NOT A, a varient of 'string theory' can then be concocted to 'explain' it is completely ascientific.
If anyone ever lives long enough that string theory finally makes a unique to the theory falsifyable prediction before the fact, they will see a form of string theory validated. Meanwhile it's tenure track fashion.