Sounds a bit off, but consider the effect of having the glass thrown into a landfill where it will be bulldozed, day after day, for several years. It is just jumping to the end of what would be the eventual outcome after a few decades of disposal.
I don't find that to be an arguable study design.
"Anti-renewable propoganda" is certainly a thing, but it's also true that many champions of renewables keep their blinders on when it comes to making assessments.
Solar and nuclear are the demonstrably effective means of producing large scale power, but they don't provide portable energy density (the kind we demand). Battery technology has finally come into the realm of competition, but that has been with extensive and persistent research for decades.