City and business officials appeared to tread water on whether to replace or renovate the XL Center, stuck on whether the choice depends on a major league hockey or basketball franchise. It hasn’t helped that attendance at UConn basketball games has tailed off or that many concert headliners like Billy Joel have chosen to take their acts to the more intimate and versatile casinos. But casinos had their own problems. The recession crippled the gaming business, forcing layoffs and the cancellation of big capital projects.