There have been other examples where copyleft products have competed with more permissively licensed products as commercial products. The results are overwhelmingly in favor of the former.
Empirically, cooperation works much better on a level playing field where your company's work won't be included in a competitors closed fork.
The license for Redict is one of the weaker copyleft licenses and should not pose any onerous compliance obligations on the most common commercial use-cases for Redict.
I have had a "popular" open source library I contributed significantly to campaigned by Microsoft to change the license to MIT, and the founder and creator decided to relicense without getting any sign offs because they felt that nobody would get mad enough to sue them.
Lawyers entire job is to make convincing arguments for any position you want, by artfully speaking only true facts, no matter what the position is and no matter what the facts are.
Of course a lawyer can and will say that you "can't" let any gpl software pollute the companys product "because the gpl prevents it", instead of saying that the company doesn't want to pay the license fee for the software.
The facts of the gpls terms may be true, and the lawyer may present them for their argument, but that still doesn't make the overall assertion true.
They can use gpl software all they want. They just don't want to. And good for them. That is better than simply stealing it which many do.
It's also merely an assertion that "most" open source software uses apache/mit/bsd wthout some numbers and citation. But that sentence could be parsed more than one way. They might have only been saying that most of the projects that use apache/mit do so for commercial compatibility reasons.