I think this is partly explained by "we need to move quickly to help", versus taking time to design and implement some sort of means testing.

I will note that PPP loans in the US are loans, and are only forgiven if you can link the funds to employees' salaries. The percentage of the loan that can be used for owners' salaries is also capped.

It was given to them to keep on their employees for the duration of the aid. The aid covered up to 90% of salaries, the percentage dependent on the revenue drop during that period.