I understand people want to control what happens once they build something. Too often do you see startups go with a permissive model only to go to a more restrictive model once something like that happens. Then it ends up upsetting a lot of people.
I'm of the opinion that what I build, I'm willing to share it and let others use it as they see fit even if it's not to my advantage.
I think the GPL mainly suffers with startups because it makes monetization pretty difficult. Some "commercial" uses of it are also giving it somewhat of an undeserved bad taste (when companies use it to benefit from free contributions while preventing competitors from getting any use out of it).
My view is that every project and library where I can peruse the source is a gift/privilege. GPL restrictions I view as a small price to "pay it forward", and to keep that privilege for all wherever possible.