Oh come on, soldering is fairly safe - the worst thing you can realistically get is a small burn. Compare that to say, cycling or skying (which is something many parents let their 10 year olds do).
Or set something on fire. Or melt something (like the cord going to the iron). It's certainly one of those things that needs a little supervision, at least for a little while.
Never had your soldering iron roll off the bench and then tried to catch it, hmm? Inevitably, you catch the wrong end...
/but you only do so once... //wearing shorts during the episode can make it double the fun!