You realize that I have played on several private server’s and reached 60 on them. I’ve hopped between them. Nostralius. Elysium. Lights Hope. Northdale.
Do you know what all these servers have in common? They stay popular. Until a fresh one comes out. Because people get bored at level cap. They want to start fresh. Blizzard’s version of the game will never offer that. You will only start fresh once. Lights Hope released Northdale. Do you know what happened? Lights Hopes population dropped into oblivion. Northdale became the big one. Do you know what happened after Silver Hand came out? Northdale died off.
You can’t expect somebody to sit there and play their maxed out character without the ability to physically advance any further or experience something new day in and day out. It’s not going to happen. MMO’s are popular because they are an ever changing world that you experience alongside other people. Not a game frozen in time. This is my opinion.