Use a little common sense: Maglev trains are constrained to a very few fixed routes. To go anywhere else, you need to rent a car or take a taxi or bus from the train station to your real destination. The cost and time and inconvenience involved in doing that means that driving your own auto is faster and cheaper for any short-haul trips (i.e., anything less than 150 miles plus the travel distance between the train station and your starting point and between the train station and your destination).
Conversely, airlines are faster than trains for any long-haul trips (e.g., over a thousand miles), even adding in the government-imposed delays at the airports. Furthermore, air travel is much more flexible, since the travel corridors are free (no tracks to lay or right-of-way to purchase). Planes can go anywhere there is an airport; routes can be added or dropped in response to consumer demand; and competition (at least in some markets) can hold prices down.
So Maglev trains are left trying to fill a narrow market niche between cars and planes, while requiring a huge up-front infrastructure investment which will probably never pay off. If market forecasts prove wrong and demand is smaller than anticipated, the Maglevs are still stuck on their existing routes. If demand exceeds expectations (less likely), it's hard to increase capacity since you can't have too many high-speed trains traveling too close to each other on the same piece of track.
That's just a sampling of the problems. For example, I haven't even delved into convenience of schedules (or lack thereof).
Maglev trains are a bad idea whose time passed thirty years ago.
Hmmmmmmmmm............
New Yawk to LaLa Land is approximately 3,500 miles. On a plane you hardly ever get a direct flight and get shuttled to some hub in say Chicago, Minneapolis, Dallas, Denver etc. So with a stop to change planes on a 600 mph jet (6 hours direct), a flight across country takes 8 hours or more. Okay?
A direct train at 300 mph is 11 hours or so. Certainly this is comparable. Yes?
Hell, Madden had to have a $50,000 bus made for him to do the play by play during this football season since he hates flying so much!