At the end of the day if the league didn't play, the players wouldn't get paid. If they were, there quickly wouldn't be a league to come back to. All but one player voluntarily opted to return to the league instead of sitting it out. One can't imagine sitting it out would have done much for their physical conditioning, competitive edge and development, whether it was just them or the whole league. It's not like those players who aren't currently playing in the NHL are all sitting at home – look at how many opted back into European leagues where things aren't any safer.
The truth is that most of the staff who aren't playing, coaching, officiating or doing medical/equipment work should be okay – with proper PPE and social distancing, it's not as though they're coming into contact with members of the public, or that too many of those jobs require intimate working with others. The risk is to the players and coaches, who are naturally in close contact with each other without means for social distancing or PPE during games.
I sincerely doubt many of those players would have been okay spending six months in a bubble, completely isolated from their friends and families. Even if their close relatives were in the bubble (even leaving aside the expense), I can't imagine many of them being comfortable living in the bubble for six months.
The Return to Play measures aren't designed to prevent anyone getting COVID – that's not possible – but to limit it as best as they can. Which is the same thing any other workplace is doing. While I'm in favour of lockdowns and restrictions designed to reduce risk of transmission within the community to the extent we can, we also have to recognise and remember that for many the inability to work or earn a decent salary can cause huge emotional, psychological and health issues in its own right. And, with far less importance attached, having things like sports and entertainment removed won't help either.
Given there is some uncertainty growing about whether the vaccines are effective against some of the newer strains of COVID-19, and the likelihood more and more will emerge over time and society will be reacting to them, not preempting them, it isn't even a certainty that things will be safely back to normal by 2022. If you hold hockey out until things are 'normal', we could be without a league for years to come.