I remember a few games which didn’t require such sacrifices from developers.

Some even commercial. Like NWN, with people making their own campaigns without, you know, any effort spent by the developers of the game itself.

Of course when the business model is milking players and making it problematic (either technically or by paradigm) to satisfy interest with community-made modifications, then all the load is on the devs or else the game becomes irrelevant. Well, guess whose fault that is.