Yes, there was that, too. Now I did not mean that the license is of crucial importance to most end users (it might be for some, but likely the other way around as some will prefer the simpler BSD clauses). But it was decidedly important for the business and consulting side to form, and that was hugely where Linux won.
Red Hat, Cygnus and the IBM service group took early big bets on Linux, which could not have happened on a product where vendors based their respective offerings on proprietary lock-ins. That drove adoption in banking and defense whose existing UNIX stacks looked increasingly old, which drove a huge industry shift that took the better part of a decade.
It used to be quite common to find people arguing that BSD was the more "business friendly" license, which is may be true in some specific ways but tends to miss the bigger picture. The adoption of a mainstream system under GPL license was important.
Then the situation was probably different in the web hosting business, in academia, and in other sectors where other factors dominate.