Well the thing about songwriting credits is they're largely vague so you don't know how much a writer did on a track. But when the QM thing happened and actual reference tracks of entire verses leaked, that's when it became a big thing. Plus QM wasn't credited for everything, ie RICO, Know Yourself, Energy, 10 Bands, so he actually was a ghostwriter
QM is credited on every song he wrote except "RICO" breh:
Drake – If You're Reading This, It's Too Late [Credits] Lyrics | Genius Lyrics
Here's the thing....if you don't know who Q. Miller is, then it doesn't matter if he's credited. That was the problem. Couple that with the fact that 40 was in interviews back in 2012 talking about "as a rapper you shouldn't need help with your bars"....well, it's not hard to understand why this is a problem even with song credits. If all it takes is a song credit to dispel ghost writing rumors then people wouldn't have wondered who A. Palman was back in 2011:
TAKE CARE LINER NOTES CONTROVERSY: WHO IS A. PALMAN?! « Kanye West Forum
Ironically crediting Hush on "Take Care" was the start of people thinking Drake was using ghostwriters. Again, because nobody knew who A. Palman was.
Fred.