Why not look at it from the reverse? If our healthcare system that deals just fine with flu outbreaks etc every year can’t cope with Omicron… maybe it isn’t as mild as everyone says it is?
We can blame both. People talking about herd immunity and intentionally filling the hospitals are going to overwhelm any system, and european countries had problems like this too when COVID was at its worst there.
Current logic:
There are hospitals that are forcing covid positive staff to work but not letting staff that has had covid already but isn’t vaccinated work.
Similar logic: shutting down nuclear power plants and then complaining that there isn’t enough power.
More similar logic: allowing decades of fuel to build up on the bottom of forests and then expressing befuddlement when wild fires burn out of control.