Meh. I agree in that in came be seen as a negative, but LA Reid doesn't have enough gravitas with the general public for this to be damaging to her. It'll probably only resonate with a small subset of MJ fans.
Also, Mariah is very involved in her business endeavors. Being with Tommy taught her business acumen, and, after they divorced, she's been doing a lot of things her way. The problem is she also needs a strong personality to match up with hers so they go along with EVERYTHING she says. She does the whole ditzy diva thing, but she's actually more shrewd and involved in her business activities than she lets on. Hell this is the same woman that got Virgin to pay $48 million to record Glitter, and to leave their label.