I don't think Maxine is leaving.
I do hope she isn't.
Maxine is indeed leaving.
I don't get it either, people like Shaun Ley and Ben Brown who have no real job and aren't anywhere as good at presenting should be the ones shown the door.
I must respectfully say that your post completely mis-frames the issue (if it can even be called that).
Let's run down the reasons why, shall we?:
a) No-one here knows whether Maxine is being "shown the door". Even if - big if - hers is one of the presenter posts that's being cut, we still don't know - and frankly, it's none of our business - whether she took voluntary redundancy, or if she didn't, whether or not she just - y'know - wanted to do something different.
b) You have no proof that Ben Brown or Shaun Ley were directly compared to Maxine by BBC bosses and found to be "better" or "worse" than her and that's why she's leaving. One imagines the number of times they've directly covered for her - and thereby provided a direct basis for comparison - is minuscule. It won't surprise you to learn that I have other priorities which mean I can't/don't want to keep track.
c) How do you know that Ben and Shaun aren't happy with the roles they have?
d) Whatever you think of Maxine (and personally, I happen to agree with you that she's great), Ben is a well-tested rolling news presenter and respected former foreign correspondent and Shaun is a seasoned political correspondent and live interviewer (with whom - full disclosure - I used to work on Radio 4). I realise it's a matter of personal taste, but you shouldn't dismiss their credentials to sit in a presenter's chair just because you personally enjoy their work less than another broadcaster.
e) For all the reasons I've outlined and many more besides, the way you've couched it simply isn't how decisions get made in broadcast newsrooms.