On the day the Sixers honored their most recent past glory, the franchise slid even farther away from the already blurry championship season of 30 years ago. Certainly not near the level of the 1982-83 NBA title team honored here Sunday in the last home game of the season, but Doug Collins at least pushed and prodded the staggering Sixers back to respectability and competitiveness when he arrived to coach in the city where he was an all-star guard in the 1970’s. With Collins reportedly stepping down as head coach, the Sixers will only go down, likely dropping next season to the low and laughable level of where the team was before he returned three years ago. “The organization can ill-afford to have Doug walk away,” said the wise Doctor Julius Erving before the game, “because they’re not going to get a better coach, a better teacher.” This day won’t go down in Sixers’ infamy as when Wilt Chamberlain, Moses Malone and Charles Barkley were traded, but there is just no possible way to slap a positive spin on Collins walking away from $4.5 million in the final year of the contract extension he signed before this season. This overhand right to the organization’s head, however, isn’t a surprise punch, even though John Langel, the Moorestown-based agent for Collins, said early Sunday evening he expected his client to return next season. Last week, a report stated Sixers ownership wanted Collins to step down after this disappointing and disheartening season, which mercifully ended at the Wells Fargo Center with a 91-77 win over Cleveland.