There's not any merit in the accusation. The government did subsidize Boeing's SST program, but the technology developed for that wasn't usable for the subsonic jets. (For example, Boeing airliners use 3000 psi hydraulics, while the SST used 4500 psi to save weight. Such required a totally redesigned hydraulic system. 4500 psi is very dangerous, spray from a pinhole leak will cut right through you.)