No, I think you're right, it does come from a lack of respect.
It's caused by one of two things IME.
Either they actually see you in the role of "wife" or woman generally as being a kind of class below them, and "women's work" as being beneath them as well. Usually this comes along with a general lack of emotional understanding/support and a sort of vague expectation that looking after the children and the house is what you like to do and basically your responsibility so if they do any of it, it's "helping" and you should be appreciative. They can get quite grumpy when you're not. Will also often claim ignorance of perfectly simple tasks yet have high standards for you completing them. Your work outside the house will be seen as more of a hobby/side thing yet they are sometimes stingy about money which you haven't directly earned yourself. This is a lack of respect on really quite a devastating scale because they don't really think you are equal to them at all. It can vary from benign-ish-but-ingrained sexism (where they think that their "role" makes up for yours) to full on abuse/control from a dominating personality expecting a domestic slave.
Or they are a kind of "modern man who hasn't quite caught up" - ie they think they are doing their fair share but their norms are so utterly screwed up by patriarchy/their own childhood/stereotypes in general that they are blind to about 80% of what you're doing, mainly the invisible "wifework" but also in terms of stuff they are actually participating in as well, like they'll cook once a week and then sit back all pleased or feel like because they give you a lie in one morning a week and do some of the childcare drop offs/pick ups that they are sharing 50/50 childcare and they completely miss that you do 100% of nights and 99% bathtimes, or whatever.
I don't think the second is so much a disastrous lack of respect because they probably do genuinely try, but they aren't really looking and seeing, they aren't paying attention, which is a lack of care, which can also translate to a lack of respect when you think of respect in terms of admiring and appreciating what a person does. The good thing is that if your partner is like this but he genuinely cares you can get him on board by communicating that you're unhappy with the current division of things and pointing out where and how it's unequal - it's just a case of catching it at the right moment and saying it in the right way - although unfortunately it may take a lot of repeating to get through because this stuff is SO ingrained, or it might be that you have to take it as a slow slog pointing out one issue at a time because to basically call your partner a shirking workshy git all in one go might get them to react a bit defensively 
Useful (possibly) stuff:
english.emmaclit.com/2017/05/20/you-shouldve-asked/
mustbethistalltoride.com/2016/01/14/she-divorced-me-because-i-left-dishes-by-the-sink/
www.amazon.co.uk/Wifework-Susan-Maushart/dp/0747561729?tag=mumsnetforum-21
I don't think working or lack of it is the cause of the respect stuff, it's underlying beliefs, although if you both work the same amount of hours, it might force more awareness of the discrepancy in house stuff - although IME the "invisible" stuff is all still there, the management, the admin, the children's social calendars and the nail cutting and so on and sometimes some more visible but seemingly unnoticed stuff like cooking and meal planning, night time parenting, and so on.