Because now there are no restrictions to speak of left and it can't go much worse. No ground for apocalyptic scenarios anymore.
Also, it's entirely up to people themselves if they want to be protected or not: Omicron is so transmissive, it doesn't matter for transmission if people are vaccinated or not - whatever impact it has on transmission is of little consequence - everyone is going to get infected, anyway (maybe a few weeks later but it doesn't matter at all).
On the other hand, vaccines are universally available, and free, for a very long time now.
Together it means that if you are unvaccinated, it's on one hand, only your own fault, and on the other hand, only your problem - effectively you no longer endanger anyone but yourself by staying unvaccinated (big difference from what it was a year ago).
Which means, there is no point for anyone but unvaccinated themselves suffering. If you got the vaccine, Omicron is about as dangerous as flu, and no one closes economy because of flu.
Almost all unvaccinated are Republicans and Democratic administration is in power...