With a car this trip is 5 hours. No one in their right mind would ever do such a trip with regionals only, it is extremely painful. In addition, the chance that one of the connections will be missed is extremely high.
Nobody in their right mind would, yeah. So they just have to pay for the train if they don't want to buy and maintain and fuel a car for such journeys. Myself, I'd never consider going by car between such well-connected cities, I'd have to drive (can't read a book for those 5 hours) and deal with parking and either rent or borrow a car (or buy, I suppose).
Question is if the 600€/annum is cheap enough for people to opt for this. But at least many companies are looking into giving the 49€ ticket at a discount - and that is actually desired from the state as the state also gives the company a discount if they do so.
Two weeks ago, the usual "person on the train line" cancelled all traffic for two hours, with the usual cascading effect for connections.
So instead of arriving at 7pm, I ended up reaching home about 10pm. I was 30 km away from home.
I always took the train unless I was doing something in the evening--in which case the train was a poor option in general. (Once you got out of commuting hours there were only a few trains for the rest of the night.)
The main improvement is that now a subscription to your home public transit can also be used when you visit a different city, this is huge. Just like a car registered in Munich can be used to get groceries on a visit to Hamburg without registering there.
The inclusion of regional trains is mostly a side effect of keeping it simple while not excluding those whose commute includes regional trains if done by public transit (which isn't rare at all, and excluding them would be impossible because they are the most well-heard group in politics).