to adapt language beyond it’s original meaning
If the executive's rules leading to Loper Bright were not reasonable, the court wouldn't have had a reason to overturn Chevron in order to decide against it.
Edit: the fact that court first wisely delegated the power to set regulatory rules doesn't change the fact that they unwisely took it back.
They made up presidential immunity a few days later, then gave themselves control over it.
The court has a long tradition of deferring to the elected branches on matters of policy. This is based on the principal that voters should have a say. If a rule is reasonable under existing law, then changing it is properly the work of the legislature.