It's not valuable or important for bitcoin to become legal tender; it's valuable/important for it to be given a status so that users are not subject to massive persecution.
As they are today, in much of the world.
Examples: heavy taxation for usage, for selling, trading. Wide scale bank account closures without justification. Ludicrous privacy invasions required to interact with a company selling bitcoin. Police and financial authorities persecuting, confiscating and generally criminalising any activity with it.
Just remove all that, that's what we care about.