You should read the article in full, and/or learn the difference between a share and asset deal. Your link is about the former, the article about the latter.
"You can have the shares for €4m or the assets for €5m". Both sides have agency in a negotiation.
AIUI the .de rules are intended for a somewhat different situation, perhaps more common. The article describes a situation where almost all of the exit is profit. I'm happy for you if you're in that situation, but I'd guess that most people have costs. In that case .de lets you set costs from past years against the exit, and I've heard (hearsay alert!) that .de gives you more flexibility than most countries.
All that said: if you have high income and no costs, German taxes are hard on you, it's true.
