I have no doubt that there are companies and/or lawyers like that. What
I doubt is that this is the overwhelming majority, as you seemed to
suggest ("...most corporate lawyers..."). All the evidence you and Sven
provided is merely anecdotal.
Mrrr. I was trying to back that off a bit; the real issue is not that it's "most", it's "enough to make ghc problematic". The last thread about cpphs (quick search gets me https://mail.haskell.org/pipermail/ghc-devs/2015-May/009106.html from the middle of it and containing a decent summary) indicated that a significant number of high profile Haskell users would be forced to drop Haskell if cpphs went into ghc, because they'd have to face the uphill battle of getting corporate lawyers to okay it again.
"Just do it and fix the fallout afterward" is not a solution; once in, those lawyers would think twice about reinstating ghc if it were subsequently removed, because that's the safe stance legally speaking.