With August approaching, the Philadelphia 76ers remain the only NBA team without a head coach. In outspoken former star Charles Barkley’s opinion, that fact is “a joke.” Appearing on Comcast SportsNet’s “Philly Sports Talk” on Friday, Barkley voiced his disagreement with the Sixers’ decision to allow their coaching search to drag on into late July. Doug Collins, their coach of the last three years, resigned on April 18, and new general manager Sam Hinkie — hired on May 11 — has reached out to several candidates since joining the organization, with Sixers assistant Michael Curry and Spurs assistant Brett Brown seen as the two front runners.