No matter how rubbish they might be or whether its better for someone else to be there instead, I do feel its the mothers prerogative to choose
OK.
So if he causes the situation to escalate leading to bad memories or panic, what then? What if a HCP asks him something and he freezes, causing a misunderstanding which leaves her 'let down'? What if as the HCP and doula I mentioned said he tries to 'man up' by controlling... "oh no you don't need an epidural because I'm scared of that fucking great needle " even when she wants one?*
So yes, she chooses. But she can't choose what happens as a result.
I hope to goodness she'll not blame him or HCP when she insisted on having someone, knowing the facts, who admitted they wouldn't be reassuring. This is the major flaw in the 'man up' thing: you cannot have what you want when it involves changing someone's feelings and thoughts. Bearing in mind that birth is also unpredictable, that's two things the woman is banking on controlling which might not work out.
And what if he has some weird reaction afterwards - perhaps with regards to intimacy or even being fearful of the baby? That won't make life easy!
Also to put it brutally we HAVE to get the baby out of us. Plenty of us get tramatised or find it unpleasant. There is a slight dog-in-the-manger "if I have to suffer it so does he" element to some posts... rather than a pragmatic "birth is a big thing, who is most useful to help make it better for me?" attitude.
As I mentioned before, I'm having DH (not squeamish at all) and my DM (big family, all sorts of births from forceps to 'popping out with a sneeze' - been there, done that, ruined got the t-shirt).