I'm an unschooling mama through and through but I'm not a stupid mama. If my child wants to go bike riding at midnight without a helmet, it's my job to say no because that would be unsafe. In my view, schooling is also unsafe. It's unsafe physically, emotionally, and because I take education very seriously, it is educationally unsafe as well. So it is likely that I would say no to any immediate request they had regarding school attendance.
Some people might say that they enjoyed school, but it's like playing russian roulette. You may or you may not do well academically, you may or may not get teased relentlessly, you may or may not enjoy what you do there. One thing is certain, it's easier to excel at something when you enjoy it. My kids are too young to know how that works, but I'm not, so I get the final say on where they are educated.
Society has a lot invested in making schools appealing to both children and parents. We need schools to churn out the worker bees that fill the most mundane jobs, the factory workers, the check out chicks, the sales reps, and the garbage collectors. Now, let's be realistic, those jobs are important in our society, but they're also unfulfilling, and undervalued on all fronts.
Despite what television shows / movies / books set in schools would have us believe, schools are not encouraging hotbeds of creativity. Not one single famous inventor, or successful entrepreneur ever credits their schooling years for their success. They all credit either their university, their family, or their life experience.
If sitcoms suddenly started portraying schools in their true light, with peer pressure, festering bullying, high stress levels, boorish classes, obsolete homework, backstabbing, sexism, smoking, rape and rejection more parents might seek out an alternative.
When any of these realities are shown in a creative dramatic context the ending is always happy. The bully learns hie / her lesson, the individual child is celebrated, safety is restored and life returns to "normal".
In reality a bullied child is rarely vindicated, a unique child learns to conform, and schooling maintains that status quo very successfully.
If my child wanted to go to school because of a story they read about school, or a movie they watched I would explain to them that what they are expecting is not the reality of institutionalised education. In reality schooling involves many hours of sitting still and being talked at, and very few hours of the fun times shown on TV.
My answer to the question "Would you let your child go to school if they wanted to?" is a resounding MAYBE. Firstly I would establish whether or not their desire was based on reality or propaganda. Then I would try and meet those desires in a home setting. Then if my child still believed that they had unmet needs that a school could fulfill I would have to consider schooling them.
I've been through it before, and each time our family encounters this hurdle to unschooling the outcome is more unschooling, and I think that's because it really is the best thing we've ever done as a family!
Unschooling 
I was recently asked what I would do if my child asked to go to school. My response was that it would depend on why they wanted to go, and whether or not that was a reasonable expectation of schooling.