I would wager that most of these supported BLM the cause (good) and donated to BLM the scam NGO (bad) out of ignorance or negligence more than malice.
I'm not as trusting or kind hearted as you are, especially when I consider food and beverage companies and of course, the pharmaceuticals.
Actually it might work to separate the good from the bad if we look at these company's behaviors in the past and not only look at their donations to BLM/Antifa.
I wouldn't call it trusting. I just look at these actions on a different axis than good to bad.
Most corporations are not malicious for the sake of malice. They are apathetic towards morals, because they are too busy minmaxing shareholder profits. Something like contributing to BLM or antifa is decided on one factor alone: Will it boost profits? That, then, more often than not just comes down to "Will it get attention?"
BLM was a hot topic. Virtue-signalling support got a lot of attention for a short while, which means that you get a lot of attention per dollar invested. If you look at how much of a an average mega-corporation's budget goes into marketing and PR it's not hard to guess how attractive such an opportunity is to a corporation, morals be damned.
Same thing for LGBTQ, Ukraine, Israel and what not.
It's all just a discount on something they spend billions on anyway: Attention.