Ever? I'll admit that it wasn't in any time in modern NCAA sports history, and has been that way before all but probably a few of us on this messageboard have been born. However, if you go back far enough, and it was quite a while ago probably at least pre 60s and maybe even 50s, it really was more of a student extracurricular activity even if there was a lot of tradition and pride involved. It wasn't run like a huge industry. I could also point out despite how long it's been going on that in no way makes it somehow right or justifies it.
Intercollegiate sports started as an alternative way for students to get in physical activity (as compared to manual labor).
As the entertainment value has grown of some sports, in many cases universities see it as an additional source of revenue. That being the reality, it's worth it in some cases to now exchange an offer (of the opportunity) to get an education for participation in a sport. A more than fair exchange IMO.
Just because all student-athletes may not be on a Phi Beta Kappa curriculum doesn't mean many don't get worthwhile educations. (The college/university experience is an education in and of itself.) Or, that the institution has somehow compromised it's academic ethics per se.
But certainly the revenue component lends a certain and natural business aspect to it but that just comes with the territory IMO.