The 'helmet' example is very different to this situation.
It is not like the tire will explore immediately if the dirvers use it. It is unsafe when they keep using the Michelin tires at high speed on the last turn.
As I said, there're alternative ways to make sure their safety, like drive slower on that turn or change tires more frequently. But doing so, it'll make the drivers less competitive, which they don't want to sacrifice even to keep them safe.
The seven teams using Michelin tires do know drive slower on the last turn can make them safe, but they don't want to slowdown just themselves. Thus, they asked FIA to break the rule to add a chicane on the last turn so "all teams" are forced to drive slower on that turn. And of course, their request was rejected.
If it was the only solution to insure safety, the rules need to be changed right away. However, it is not the case here.