So, why so many Skyrim releases? It's simple: People keep buying it and people keep playing it. Bethesda's own Todd Howard talked about this very thing with Geoff Keighley during Gamelab in Barcelona. GI.biz sat in on the interview and provided the following quote from Howard.
"Even now, the amount of people who play Skyrim seven years later; millions of people every month are playing that game," Howard replied. "That's why we keep releasing it. If you want us to stop releasing it, stop buying it."
I mean, he's not wrong.