Why did people in 1918 think masks were unhealthy?

Because they forgot to consult with lord lestermount first

I do not know but they were the most likely to die from Spanish Flu.. That was 1918 I believe.

They died in larger numbers too after being fed misinformation by conspiracy freaks.

“There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge.” ― Isaac Asimov

It is no surprise that pretty much all of those people are DEAD!!!

Stupidity is not limited by time and space. It occurs everywhere all the time.