I would say no matter what, your DH should go to a class on childbirth. In the event that you experience a traumatic birth and need to process the experience afterwards, he should know what you are talking about and you should be able to talk things over with him. Hopefully you won't be scarred by the blessed event, but it does happen sometimes. So he should get educated about what's about to happen no matter what.
I also think men generally want to see and hold their babies, and many genuinely care about the welfare of their wives and worry about things going horribly wrong, and want to be there to do the best they can for them or for their babies. The instinct to protect if you will.
I think historically speaking maternity care has improved since men started being admitted into delivery rooms, with much less of a meat factory approach and much more effort made to accommodate approaches like natural birth, water birth, birthing balls etc. and a trend towards home birth has followed. I'm not sure if the admittance of men was the catalyst for these improvements or if the improvements had already got under way when men started being admitted. However, it's notable that in places where women generally labour alone/with other women, infant and maternal mortality rates are high.