It is a stereotype, but the statement itself is not an exaggeration. An average user has most of the software he needs even in linux. It is not foreign to the user if it is the first one (if it is default) he/she encounters.
"Average" user must have used very limited amount of software. I agree, not everyone need software for modeling or design, but again, looking at Grammarly, which is pretty useful addon, and it's only available for MS Office. "Average user" may start from Libre Office, but end up disappointed, why addon developers don't care about him. And they don't care (well, maybe just deeply concerned), because investing 20-30% of the whole development time for supporting 1% of user base is financially pointless idea.