For the ones who don't live in Germany: it's just for regional trains. So for instance if you would like to travel from Dusseldorf to Frankfurt (~200 km) people usually take ICE trains (direct, around 1h 45min. and 90 euros if you don't buy the ticket in advance).
On the other hand, if you are planning to use the 49 euro ticket... well, you either can't make it for the time slot you want, or you'll spend 4h-5h (best case scenario) with multiple changes in between. Also, regional trains are not like the ones one see in the movies: they are usually crowded, noisy, not that clean, and they are not always on time... which is rather critical if you are changing trains many times (ICE trains are more like the ones you see in the movies).
On the other hand, if you are planning to use the 49 euro ticket... well, you either can't make it for the time slot you want, or you'll spend 4h-5h (best case scenario) with multiple changes in between. Also, regional trains are not like the ones one see in the movies: they are usually crowded, noisy, not that clean, and they are not always on time... which is rather critical if you are changing trains many times (ICE trains are more like the ones you see in the movies).