Well I'm certainly not anti-extending him, I'm just pointing out that "best receiver the Ravens ever drafted" isn't a good enough reason to extend somebody.
As for the contract itself, I think 5 for 75 is quite a bit low. In today's market, that puts him as a back-end top 20 WR. I'll concede the market for WRs is a little hard to decipher, given that you got guys like Kupp, Diggs and Adams who are significantly underpaid. But I also see guys that I think are significantly overpaid, like Amari Cooper, Kenny Golladay, Allen Robinson, who are making $18-20M per.
So when I look at this, I say to myself, if Hollywood hit the open market, how would he do? Well your premier WRs almost never end up in FA. The best FA WRs you'll find are the Allen Robinson, Kenny Golladay, Jarvis Landry types. Good players no doubt, but they're not like elite level players like an Adams, Hopkins, etc.
So these guys routinely get $17-18M a year on the open market in TODAY's market. And in my opinion, today's market is quite a bit lower than the market will be in two years (when I think Hollywood gets extended) or even next year. I think $18M a year is about the low point that Hollywood would get on the open market in today's NFL. If that's two years from now, I see plenty of scenarios where he's a $20M WR.