This article from Cracked will explain the entire debacle more thoroughly, but I'll break it down for you.
PBR is brewed and packaged by MillerCoors. However, their partnership expires in 2020, and by the looks of it, MillerCoors doesn't plan to continue it. Pabst is pissed because the original contract allows for two five year extensions. MillerCoors not only says they have no actual obligation to enact those extensions, but that PBR costs too much to make for it to be worth the extensions.
Now there's a lawsuit and a bunch of legal stuff and yada yada yada
BUT WHAT ARE WE GONNA DO WITHOUT PBR??
Now no one is pretending it's a "good" beer. But when you're living on instant ramen, and need a cheap beer that doesn't taste entirely like garbage juice, PBR is there for you.
When you're throwing your first college rager, and you need to get beer for 100 people, PBR has you covered.
When you're in one of those weird bars with nothing familiar, but they need to have ONE thing for people to fall back on, they choose PBR, and so do you.
Hopefully this all gets figured out, or else 20-something culture as we know it will be changed forever.