Blame it on the accountants
Increase of distillation proof
and the corresponding
Increase of barrel entry proof (and/or the water needed to bring it down to 125)
I'm still begging to anyone who is listening to please make me a whiskey that is distilled to 100 proof, entered into the barrel untouched, and bottled 5-10 years later untouched. Please! You can just take all my money!