“Never attribute to malice that which is adequately explained by stupidity.” (or carelessness in this case)

I'm fairly certain they're both malicious and stupid.

I would attribute it to profit motive instead of either stupidity or malice.

FWIW, I used to love this phrase but over recent years have come to understand it is quite damaging. We live in a society where evil frequently hides behind a ‘stupid’ label, and people bring this quote up to defend or soften actions that are indeed done out of specific malicious intent.