Originally Posted by: Roland 
Absolutely - I would hope it's entirely designed based on functionality :)
Exactly, this was the major message from the DB introducing the new ICE 4.
It is designed for the user and not for the viewer.
Anyway, if you sit inside, you don't see it. If you stand outside, he is passing as quick as that you see it only for seconds not minutes. Where is there a design problem?
Even the reduced high speed of 250 km/h is due to the German circumstances with a large and dense population. The trains stops at an average of approximately 100 km. So an excellent acceleration to achieve a high speed is much more important than the high speed itself. (just for remembrance: in Germany live 230 people on one square kilometre (sqkm) - in GB 276, USA 33, NZ 17,5, Canada 3,6, Australia 3 people on 1 sqkm.).
For example and very impressive to myself is on every occasion the track section Goettingen – Hannover of the ICE line Wuerzburg - Hamburg. A distance of 99 km and the ICE needs exactly 30 minutes from platform to platform. Even including speed-up and slow-down. For speed-up and slow-down for a stop an ICE shall need 6 minutes more instead driving through non-stop. I read this once in a DB paper many years ago, using the so called sprinter from Munich to Frankfurt/Main.
Another reason is, that at the moment are only 3 lines licensed for a speed of 300 km/h. The longest line is between Köln (Cologne) and Frankfurt with about 180 km. (The others are Erfurt – Leipzig, 120 km and Nuernberg – Ingolstadt, 170 km).
Although it changes almost daily, but at the moment the high speed track section Erfurt – Leipzig is only served with ICEs at a speed of 230 km/h, although 300 km/h are possible. This line is at the moment the only one with the ETCS 2 (ETCS = European Train Control System) equipment. Over 120 km you see absolutely no signals! But when they opened the line December 13th, 2015 (not a year ago!) the DB had only 3 trains licensed for using ETCS 2.
Perhaps this is my wish for 2017 to Maerklin: bring this ETCS 2 system also in H0! Should be possible with the new CS 3+!
At least there is the most important point not driving more than 250 km/h: economically reasons.
I guess, any engineer here will approve that with rising speed the consumption of energy is rising as well, progressively.

The same is with the maintenance costs. I think, we should not believe what a press is writing without thinking about it.
Sometimes a little less is much more.