To be perfectly honest, as an elementary school teacher, there are times when parent volunteers are great, or like field trips indispensible, but for most things, especially parties, having them is a whole lot more work than not having them.
Quoting myself to be clear.
First of all, I want to apologize I'm home today because my mom is having major surgery, and distracting myself with DIS because I'm too worried to concentrate on "real" work, so that came of snarkier than I meant. I was also reacting to that specific post, not to the thread as a whole.
Here's where I come from: I have done all my teaching and am now an administrator in programs where there's not a lot of parent volunteering. Teachers seem to survive without a lot of photocopying and laminating (I'm not even sure what they're laminating -- can someone clue me in? We laminate things once in a while, for example, the PK kids make placemats for snack but it's a once in a while thing). We teach our kids to open their own milk cartons, or ask a classmate for help. The lunch ladies hand out ketchup with the meals and if you forget it you walk back and pick it up. Parties are low key things, with an emphasis on student achievement -- wear your pajamas on the 100th day of school and listen to a special story, an authors party where each child reads their most recent piece of work, has a cookie and goes outside a few minutes early for recess -- the kids are beaming with pride the whole time, seems to work. We do have parents come to school, kids put on plays, and other culminating events like museum like set ups in the classrooms where kids show what they know, but in those cases the parents are there as guests, not because they're helping the teacher but because we want them to know what we're learning. Field trips are the exception, in that we do like to have enough hands when we're walking the little ones to the subway or whatever. Except for field trips, parents are welcome to bring little siblings for all of these things. It does seem odd to me that you would exclude siblings from a performance.
On the other hand, for Kindergarten I sent my son to a school that seemed like it would be familiar to many of the parents here. Parents volunteered a lot. I remember classroom parties where 10 different parents brought food, and had the kids making crafts. I went along, baking egg free/milk free snowman cookies, and figuring out how to use pony beads and pipe cleaners into snowflake suncatchers. The resulting party felt chaotic, and wasteful. Kids seemed to be learning that fun is about sugar and getting out of work, as opposed to the lesson of finding joy and pride IN your work, that kids seem to get at our school. Teachers also seemed to spend hours communicating with parents about these events, cleaning up after the events (classrooms were trashed when they were finished), and seemed exhausted by managing a room full of kids who were having trouble figuring out if they were following "Mommy's rules" or "School rules".
I will always welcome parent volunteers in my program, because I think that it benefits families to have this experience. But if you come in with the attitude that you're making some sacrifice and doing my staff a huge favor, then please stay home. Also, if it really is a sacrifice for you, because you work or have younger children, don't feel guilty, reach out to me and I'll help you prioritize events, and figure out other ways to feel equally connected to your child's education without compromising your other needs.
Again, sorry I was blunt the first time.