All frames and wheels used in UCI-sanctioned races must pass UCI safety tests. The weight limit was not introduced for safety reasons but as a result of the Lugano Charter, which stated that technological development was inherently antithetical to the sport of cycling.
C.f. the hour record. Until recently, the rules essentially stated "the hour record must be attempted on a replica of Eddy Merckx's bike circa 1972". Rules for the hour record banned streamlined helmets, aero bars, disk wheels and frames with non-round tubing. These rules were introduced directly as a reaction to the battle of engineering an ingenuity between Obree and Boardman.
Right, I'm not saying it's specifically about safety, rather that a battle of technology was decided for some reason to be worse than the added marginal excitement of lighter bikes. In F1 that reason was (originally) safety, in bicycling it's something else.
C.f. the hour record. Until recently, the rules essentially stated "the hour record must be attempted on a replica of Eddy Merckx's bike circa 1972". Rules for the hour record banned streamlined helmets, aero bars, disk wheels and frames with non-round tubing. These rules were introduced directly as a reaction to the battle of engineering an ingenuity between Obree and Boardman.
http://oldsite.uci.ch/imgarchive/Road/Equipment/The%20Lugano...