Why aren't engines designed with proper crank locking?

[Krikkit]

Looking at the timing end of my friend's EA888 in his Golf, and it's a bit of a minefield. Once you've removed the harmonic damper the timing pulley on the crank is free to move around, they've even changed the special tools to try and combat it as the dealers have knackered multiple engines.

Question is, why are they built that way in the first place? Surely there should be an ability to lock up the crank easily for service? Once upon a time you could stick a pin in the crankshaft, then either a bladed tool or a couple more pins into the cams and it was job jobbed.