its the default for all reddit/lemmy/other style platforms. The default assumption is of course everyone (in general) will upvote their own post. So setting it by default no one gets an advantage.
and what you’re asking for is a disadvantage to your posts
I get you don’t mean this so broadly but you lose all nuance with this statement.
Protect them from every minor mistake or risk that could ever possibly happen, and smothering them? Sure.
Someone about to stab your kid? Protect them from predators? Protect them from various risks and hazards in life which every parent should be teaching them?