I think there are two separate things :
1) Mark had "troubles "in his private life, both in 90-91 and in late 79-early80 with his brope up with Holly, so of course he was in bad mood, and likely it influenced his behaviour.
2) Mark wants to lead and control all things, but it's not a critic, it's just that his songs are his babies and he wants to play/produce/record them the way HE wants, and nobody else, so he tends to have this "dictatorial" behaviour that is described in the Oldfield book, and of course, it can be hard for other people which are working with him, and it doesn't depend if he is in bad mood or not, that's all.
Of course, if he is in bad mood too, it could be harder !
People like John and Guy accept this (JOhn says it in the oldfield book), others don't.
imho, both choices can be understood : some musicians accept to be hired musicians and play what you're saiing to them what to play, others can't accept that.
It only depends if you want to be a "follower" or a "leader"
I think that if you want to play with Mark, you have to be a "follower" and keep you own ideas for yourself, that's all
It's not bad, it's not a crtic, it's just the way it works with him, like many others in music industry
few bands have a "democratic" way to work, i.e, all band members can express their ideas
first that comes to mind is Queen : although some leadership by Mercury, I think that all members had the opportunity to compose songs
Genesis, Yes, Floyd at some times, tended to be "bands", but always came a time when a member wanted to take the leadership
Ego is often the main problem in a band
For MK/DS, there wasn't "problem" at all. All things were "clear" at the start. John says it in the oldfield book : the "band" was just a vehicle for Mark's songs
I f you agree, fine, if you don't, leave the band. That's all
So all that is said about Mark during years by other musicians who played with him is not surprising at all. From the beginning,it was that way