There are indeed several sides to any dispute. I speak here as someone who has had work published by people who have subsequently gone to the lengths of winding up one "front" company in order to avoid paying their contractual debts to me and to others, pretending that the business was not financially viable, and who nevertheless have continued that business, uninterrupted, through a new "front" company: presumably, the business was only unviable if they paid the bills. Companies legislation in the UK and many other countries is so biased and open to abuse that it is virtually impossible to ensure proper treatment for freelance workers (which includes musicians); the current government promised to rectify the situation, but has so far done nothing.
I have also been prevented from re-publishing work because, without my knowledge or consent, rights in it claimed unilaterally by the people who originally commissioned it from me were assigned to other publishers who have no interest in ever re-issuing it, but who nevertheless are quite prepared to use their financial muscle to prevent the originators of the material from doing anything with it.
Much of this probably amounts to an unlawful restriction of trade; it is, however, pretty well impossible for ordinary people like us to do anything about it; we simply do not have the money for the legal fees.
Of course, I have no idea how far my own experiences in another area of publishing might parallel those of people who have in the past dealt with Mr. Bulmer, though I do know people who have worked with him, and have heard curious stories. Clearly, however, I am less than inclined to give such people the benefit of any doubt: "By their works", as the saying goes, "ye shall know them".
Nobody, so far as I know, is complaining that Bulmer refuses to invest his own money in re-releasing their records; they are, however, complaining that he refuses to release to them rights which he has for many years shown no signs at all of wishing to exercise in his own behalf, which would allow them to re-release their own material and perhaps make just a little money out of it before they die.