I'm not sure why this author is further propagating FUD that suggests GPL code is unsuitable for commercial use. Just because companies are irrationally afraid of the GPL doesn't make it true.
My understanding is that if you link to the library, your code must also be GPL, which means that anyone linking to your code must be GPL, etc.
This is a problem if you're trying to sell your code. Probably you don't want to make it GPL, and you probably don't want to force your customers to make their code GPL.
I think relatively few tech companies are trying to sell their code directly these days. Most are hoping to build a product and/or service and then charge customers for access to it.
Or are you saying companies should be more willing to GPL their products? That's unlikely to happen.