"But they're still both guns!"
Everything is safe under "normal conditions"
The problem is that normal people are fucking stupid. Imagine the shitstorm when someone disassembles one of these to "see what's inside."
Saying that is like implying that everything is intrinsically safe, and it's humans which will invariably mess things up just because it's possible. In a way you're right, people will do stupid things regardless, but things are designed/exist as (less) safer than other things. Guns kill people under normal conditions, knives cut people under normal conditions, tear gas aggrivates parts of peoples' eyes under normal conditions.
It isn't easy being the parent of a six-year-old. However, it's a pretty small price to pay for having somebody around the house who understands computers.