This article, Sprint's chairman: US networks are 'very, very bad', originally appeared on CNET.com.Those would be fighting words.Masayoshi Son, who serves as both the CEO of Japanese carrier SoftBank and chairman of Sprint, railed against the wireless networks in the US as he made the case for why Sprint is poised for a turnaround."When I come to the [United] States, this network is not something you should be proud of," he said on Sprint's quarterly conference call with analysts. "It's very, very bad."This is not the first time Son has employed this argument -- he did it a year ago as he made the case for why he should be allowed to combine T-Mobile with Sprint, a notion that the US regulators quickly squashed. But his appearance on the Sprint call is a signal that he is ready to fully support the US carrier, which he acquired two years ago, and push it to improve the quality of its coverage.