Lupusina is just so right; it's about home being a safe place to let off steam.
Adults do it too: dh regularly used to come home and whinge and stomp about things at work- but when I asked him 'have you said this to the boss', he'd fall silent and look sheepish. Because he didn't really want to rock the boat, he just wanted a safety valve.
It's not because he loves his boss more than me, really it's not.
School is another classic, the number of children who throw wobblies or behave badly on the way home from school. They will be very tired after a long schoolday, so it's likely that any pleasant behaviour they are capable of will have been used up long before you get them home. They also usually adore their teacher for the first couple of years, and believe that teachers know everything better than Mummy. (Doesn't matter if teacher is a complete ignoramus and Mummy has a PhD in zoology, what teacher said about those tadpoles has got to be right.)
And then there are friends with more affluent parents, who will throw bigger and better birthday parties or take them out for wonderful treats or let them play with a big friendly dog, when you haven't got the space for as much a a guinea pig.
As a parent, you have to learn to be generous enough to accept that other people can give things to your children that you cannot. It doesn't matter: you're still the Mum and noone else can take that away from you.
It is of course up to you to decide whether you want to/need to work. But if you do, then chances are your ds will be tired enough for a wobblie regardless of who has been looking after him in the day.