As a teacher I often get asked to tie laces and at times I have done it myself and other times have asked other students.
More so because it tends to happen after lunch and that transition period is often spent with me clearing up playground incidents amongst other students so it's easier for me to ask another child.
In the all time I've done this I've never had a student have a problem either being the person tying or having their laces done.
I do challenge the kids to try it at home if they are from my class. I show them how to do it first and make them try it in front of me - but that's only because I have one or two that haven't nailed it. Then I give them high gives once they've got it down pat! Kids actually feel really proud to independently tie their laces in my experience.
In saying that I don't think it should be expected of me - nor should I expect to get wee on my hands as an early school teacher.... I never have (to my knowledge - haha). But I've also never associated tying laces with getting wee on my hands!!
I do think it's important for them to be taught and learn the skill and unfortunately due to the tight restraints in my curriculum I'm to teach - home is really where it needs to take place.