1) The build-up of "gunk" that needs to be cleaned out.
Smegma. It's a white substance made up of skin oils, moisture, etc. It is pretty bleh in itself, but it does have some purposes like acting as a natural lube. It's if one does not wash it away that it becomes dried and gross - and I don't think that'd be easy to do. If you wash it after intercourse, no problem. How do you wash it away? Pull skin back, wash with water. No soap is needed, but some may like a mild soap.
Women can also get smegma - so should we cut away the labia? Of course not. I see little distinction between cutting away the labia and foreskin and they should only be done for medical reasons or by one's choice when they are old enough.
I'm uncut and I've never, ever had smegma.
2) The fact that he is circumcised, so he wouldn't know how to mentor his uncircumsized son about the mechanics of cleaning said gunk, or peeing, or whatever else it is guys need to impart to their sons.
Hold willy, pull skin back if necessary, pee. It's not like it's rocket science.
To clean: pull skin back, wash with water.
Easy.
3) That the kid would be ostracized, especially due to locker room experiences.
"Ha ha ha! You have an unmangled penis! Nyah nyah nyah-nyah!"
Seriously? If someone said that, is that even worth bothering with? If someone said it to me when I was a kid, I'd've just laughed. Considering a growing percentage of Americans and Canadians are not being circumcised, it's not going to be that shocking.
All seem pretty legitimate concerns to me.
They seem rather... silly to me. Silly and ignorant of what it's actually like.
What do you all know about this "gunk"? Does that increase likelihood of infections?
Supposedly keeps the glans moist during intercourse, (as opposed to needing lube) which is why one should wash their penis after sex.
It only would increase the likelihood of infections if you've got disgusting hygiene habits.
Also, you don't get it as a kid. (
Source) So, that's no reason to cut off a perfectly natural penis part. There's myths that it causes cancer and stuff - but there's absolutely no evidence to back that up at all.
Again, to prevent it: pull skin back, wash penis with water.
What of ostracization and father-son talks?
I never had any talks and I've come off alright
but I wrote how simple it is to talk about it: the only difference is "pull your foreskin back", pretty much.
It's not like the penis has suddenly been replaced with a bonsai tree or anything, it's just in its natural state.