This is what happens when you're a dope rapper but haven't built up a BRAND... usually a label will come to you & offer for you to write for one of their own Artists/BRANDS until you've built yours up. Drake was offered a Publishing Deal as a WRITER for Interscope like a year or 2 before he linked up with Young Money because he was a nobody at the time...
This is pretty common. A lot of Battle Rappers like Serious Jones have made good money Ghost Writing for other Artists. Rappers like Billy Bathgate, Cap.One, etc also have made solid money behind the scenes because their Songmaking/Pen Games were solid. Wouldn't be surprised if QM starts to push himself more since his name got bigger after the Drake fiasco...