Hmmm. It depends on how honest you are being here about how much time it really takes.
My DH cycles. The year I finally put my foot down and said enough events, he'd booked seven (so same as you).
It's not just the day of the event, it's the planning, the training (you really are doing all these events on one training run a week?) the money spent in kit, event fees. Travel expenses etc.
It's sheer amount of family time revolving round one person's sport. I'm perfectly happy to look after my children but it's also nice to spend time as a family, even if you aren't doing anything in particular.
And no, standing on the side lines in the cold/wet with bored small children waiting for a flash of Mummy/Daddy going by is not a fun way to spend an afternoon.
I found that the more events agreed to the more were planned - which is exactly what you are doing, it's going to go from 6 a year to 11 a year to get your 40 completed.
My DH took my feelings on board and we have a much better balance now. He still cycles a lot (about 10 hours a week) but it fits in with our life better and he has cut down his events.
I wasn't "jealous" of his sport, as some people have said of your DH. I just missed him, as did the kids.