I feel very sorry for the male worker at the OP's nursery. And also a little impressed that despite knowing there is this much venom when it comes to males in "traditionally female" roles, he is still prepared to do it.
As women, we spend a lot of time fighting for equal rights to men, there are more female police officers, more female doctors etc etc. It's sad to think that while we're happy to fight for equality for women, we're quick to ensure men are not equal in certain types of roles. It reminds me of the Friends epiosde where Ross and Rachel get a male nanny:
Ross: Oh, come on, Rach, he's a guy!
Rachel: So what? He's smart, he's qualified. Give me one good reason we shouldn't try him out.
Ross: Because, it's weird!
Rachel: Why?
Ross: What kind of job is that for a man? A nanny? It's like if a woman wanted to be...
Rachel: Yes?
Ross: King?
I think its sad that there is a world where we'll tell our daughters they can be anything they want, but tell our sons they can't do certain jobs because people will think they are odd, on a par with the child-catcher from Chitty Chitty Bang Bang.
When I was at primary school in the late 80's / early 90's, throughout my junior schooling, I had two male teachers and two female teachers. The head was a male, it was an equal split of the sexes. DD is in school now in there is one male teacher in her entire school; every other teacher, teaching assistant etc is female. I find it a bit sad.
My DD is nearly six, she has no issues with males helping her out when she needs them to.
With regards to the OP and the comments about sparing patients dignity by having a same sex person in the room, well, I am a firm believer when it comes to certain medical issues, you leave your dignity at the door. Whether they are male or female, these people are doctors who see the human body in a medical way. I would have no problems with a male midwife, male nurse etc. DH is pretty much of the same opinion and has no issues with a female doctor.
Out of interest... for those still reading... if anybody has an issue with a male worker taking your female child to the toilet etc, do you have an issue with a gay female taking them to the loo?