I would not castrate a dog unless it were for that dog's benefit. Bitches are in season for such a short time and it's not difficult to keep them separated.
Your vet will tell you that castrating will prevent prostate cancer in later life and this is true, But not all dogs, as in humans, develop cancer of the prostrate. You can have them castrated(your dog, not your husband

) if symptoms of prostate trouble appears.
Having said that, I have , with great reluctance, had a young whippet castrated recently. He could detect a bitch coming into season a good two weeks before even she knew about it and would then fret himself to a hat-rack and as I have mainly bitches he was a permanent skeleton! And didn't we know about it

with his constant wailing.
Our other boys only get interested when the bitch is absolutely ready, a matter of a few days.
So, for his and our sanity and for his well-being he was "done".
And, yes I dare say there will be the odd accident and a litter of mongrels (not designer dogs) will be born and will have to be found good homes or kept. This will only make people increase their vigilance.
In nearly fifty years of keeping and showing dogs I have had one mishap, a litter of pug/whippet cross. The ugliest dogs you have ever seen but all found permanent homes and lived to a happy old age.