The scope creep is already here; we're soaking in it!   

It may be an intrinsic entailment, as removing the diff bomb effectively creates an eternal PoW coin, which is equivalent to a codebase+protocol divergence bomb when ETH goes PoS. 

And (especially) for fans of PoS, that is controversial.  (Let's note many PoS supporters think PoW causes climate change and wastes energy, so they are ideologically bound to that preference with very tight couplings.)

But I take your point.  We can do the minimum now, and put off the controversial until an issue is forced, thus providing clarity and defanging controversy.