The feminist boards are a public space. Anybody can post there. That doesn't mean you won't be flamed if you come on spouting sexist shite.
To combat this default parent stuff you've got to actively rope DH in, let them know that it's happening, because sometimes they are a bit oblivious to it. If that means tagging out and saying can you make sure the DC don't disturb me for a bit, then fine - after a while you'll find that he's more aware of when you are/aren't able to be disturbed. And have a blanket rule of no talking through the toilet door once you're old enough to understand the concept of waiting.
And although I do agree sometimes the mum can get narked at the dad making the wrong decision, but this is not a woe is me ohh it's impossible I can't get anything right because she just changes her mind randomly, she's more narked that he hasn't actually bothered to use his brain or engage with the shared values/household rules they have for their child, and has simply gone with the easiest answer, whereas she feels like she has to weigh up every decision because she knows that it's going to affect her in the future, whether that is a totally hyper child up past bedtime, or a child who isn't going to eat their dinner, potential puke situation, or something long term like developing a habit for sugar, tooth decay, general undermining of goals. Yes, men, this is EXHAUSTING, especially when you are the only one doing it. At least when there's two of you doing it, you can both have some lazy moments where the answer is "yeah whatever". Otherwise she always has to be "on" to make up for your laziness. So have some appreciation and respect for what your wife is doing and try to keep up. You are not merely babysitting this small human, you are jointly responsible for its development and entire early life, so use it wisely.
(Both) don't disagree in front of each other unless it's a hill you're willing to die on or a simple filling in of information which would have changed the other's decision. Talk about it later if you disagreed.