Because the Cubase users WANTED it like that.
The first implementation of the automation system caused a big uproar on the Cubase forums because they simply didn’t understand it.
The forums were on fire, and after a series of polls, the users voted on masse for the old automation system, no matter how much we tried to explain that it was identical to using “write to end”.
Same for VCA’s. The new grouping feature set was very good, and was covering everything that was needed for music production., ut it wasn’t correct and good enough for audio post. Cubase users didn’t want the extra layer of complexity, so the request was granted to not change anything for the Cubase users.
I really don’t want to go into discussion about that, I have had my share of sh** trying to explain the differences.
I have learned that explaining stuff just makes things worse.
People want things the way they want them, and they tell you when they want them.
Anyway, the answer is: Because Steinberg has listened to their users.
Fredo