How long can vegetable-based foods be stored at room temperature?
This is not an argument you can win. Say your prepared food item is a raw carrot. Clearly carrots are safe at room temperature for weeks and months. They might get rubbery and unpleasant, but they aren't going to make you sick. You can probably even prove this. Now consider a bowl of chicken stock. Rich in both nutrients and water, bacteria are going to love growing in it and even an hour or two at room temperature might be dicy. And between those two things you have items like baba ganoush which, yeah, is probably ok for a few hours. But that's not the point.

Inspectors and rules can't do "spectrum" and they can't do "read the ingredient list" or "read the ingredient list and cooking instructions" (since raw beaten eggs would poison you way faster than a hardboiled egg would.) They need a simple rule that inspectors and vendors alike can understand and enforce. The actual facts of how that particular dish spoils do not and cannot come into it. Customers, vendors, and inspectors need to see at a glance "yes, this place is following the rules" not "well, that might be ok but I'll need to see whether or not they have icing sugar in this version". 

It's not about what would be safe at home. It's not about the science of bacteria growth. It's about overall consistency and overall safety. A beautifully-optimized set of rules with 10 or 20 or 50 categories might feel fairer, but would confuse entry-level employees, require tons of signs, labels, written procedures etc, and a vendor would never be completely confident that an inspector wouldn't say "this isnt A-1B dip, it's clearly A-2B dip and I'm writing you up!"