They have been enacting a "no options" policy from the beginning but weakened it with the Gimme and the Mulligan. With regard to Unplayables, the Mulligan is a partial answer: Rehit the shot from the original place. This is the easy part, I agree.
Alas, I can imagine good reasons not to use the Mulligan to this extent:
The golf purists, demanding the full execution of the rules, would protest to get the other options, "within 2 club lengths" and "back on the line to the flag". These being very difficult to program - imagine all the mapping involved - might hold them back.
And, giving one option would ignite other demands: ball changes, water dropping, ...