A few other commenters have touched on it, but I'll go ahead and say it -- the UCI really needs to drop the minimum weight limit which I think will be an effective disincentive (along with more draconian life time bans).
They are artificially holding back the state of the art in a way that promotes cheating (if you need to add weight to your bike to make the limit, why not a motor instead of dead weight.)
The same thing has been said about Formula 1- the cars are power-limited, minimum-weight-limited, and so forth.
But even a cursory look at racing history explains why. Group B Rally springs to mind. More power & lighter weight aren't really going to make racing that much more interesting, just more deadly.
FIA has tried to shift innovation to other aspects, e.g. ruling that an engine has to last at least two race weekends (setting a floor on durability sacrifices).
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.
I don't think the minimum weight limit (I think 14.9 lbs), is much of a big deal. In fact, not having it would temp companies to push the envelope beyond what is safe. I've seen bikes that at 12 lbs (I think BH has one) and that is pretty much the point below where you start seeing really risky changes.
They are artificially holding back the state of the art in a way that promotes cheating (if you need to add weight to your bike to make the limit, why not a motor instead of dead weight.)