[mysterydip]

The problem is many modern games are designed for maximum monetization and a shelf life. You want a community enough to keep people playing til [game name +1] but not past that so people all buy the next one. Allowing players to make custom maps and modes would let them bypass the carefully crafted progression and DLC systems put in place to extract more time and cash.

[ethbr0]

Dev/publisher consolidation & ballooning AAA budgets due to higher fidelity graphics drove this.

It used to be, you did anything you could to sell more copies of your game, for as long as you could.

Now, the above mostly cannibalizes yourself, since there are so few other publishers around.