Looking after children alone etc. is a sacrifice of course, but so is having to be away from them. It certainly isn't a picnic going to sea and leaving your family.
I don't know, I was surface fleet for years before leaving when pregnant, I actually didn't mind the routine of being at sea and the runs ashore, although thankfully this was before 9 month deployments started creeping in. I found being at home when he was away a lot worse, of course everyone is different, but just because someone else is miserable about things too doesn't make it any easier. People are probably negative because a lot of the time it's painted as being romantic, and can keep in touch and have this wonderful reunion; having been both sides, the reality is often different. Obviously if OP had come on asking something else and everyone was saying how much it sucked that would be weird, but asking for honest opinions it's fair to give them. Again, it's just how you want to live really, for some it works but for many it doesn't, and often whilst one builds their career up, the other finds it hard due to being a trailing spouse or having to take the entire burden of children's sickness etc. Could be worse though, he could be a marine 
@DigOutThoseLemonHandWipes there are quite a few allowances such as GYHP, sea pay etc that add up quite nicely, so on top of your wage you will take home more, although it can varies month to month. Compared to others in the military it is good pay, and accomodation and food are free at sea and heavily subsidised ashore (including married quarters if you opt for that). If you want to buy a house though you pay the normal amount, but there are help to buy schemes so it can be easier to get on the ladder. You also don't need quals for a lot of trades, so for someone who doesn't have any the pay is very good compared to some civvy roles. I don't think any pay is enough really for having little control over your life.