Because Diablo started the subgenre and PoE is the current uncontested king. Every game in the genre gets to be compared with it. Sure beats reading random ramblings from (apparently senile) nostalgia fags.
I puked in my mouth reading this. I would take Diablo 3 over PoE like any day.
Dunno about Diablo III because I never played it and never will because of the WoW-clone artstyle, but I'm playing POE right now for the first time and it's absolute shit compared to Diablo II LOD.
There is absolutely no discernable story in POE, nor is there any consistent design philosophy so I find it very difficult to implement my own story roleplaying wise using the preexisting lore.
Titan Quest in comparison also lacks a story, but given the Greco visual design and main quest to defeat Titans, I was able to mentally visualize somewhat of a plot given my vague understanding of that time period.
Between POE and Diablo II Resurrected, I would totally recommend the latter to new players who haven't played either game yet.