If they invested in their infrastructure...
All the networks are guilty of not upgrading their infrastructure to cope with all the new connections being sold (be it phones or USB dongles). Now the infrastructure cannot cope and their only option is to limit the services their customers are paying a lot of money for.
Can you imagine energy companies doing the same? Actually, I had better not joke about that, in a few years time we won't have the means to produce all the electrical power we need. Dark times ahead, literally.