Irresponsible mostly. Bahrain has already said it plans to hold their Grand Prix in an empty grandstand.

I do think the host tracks would prefer to have a full Grand Stand, due to ticket sales, but I'm not sure how much it would affect F1 as a whole.

Sadly, there seems to be a sense of invincibility almost towards the virus in Western Countries until all of a sudden it arrives and you are dealing with hundreds or thousands of cases.