Everybody wants to sue. Suing is like winning the lottery if you win. JACKPOT!
Of course nobody really wants to put in the time to lobby their state and federal representatives for changes in the law. Such law changes could take years and years and several sessions of congress. That might take too much time and they want to win their jackpot now!
Instead of suing the company or changing the law to make carry at work legal by choice over the wishes of business which business (especially rich and powerful big business) will fight tooth and nail, it might be a lot easier to change the law such that businesses are not liable for the use of firearms carried legally by employees. Absolving the businesses from liability would go a long way toward many businesses allowing such weapons at work and businesses may be inclined to support such legislation because it reduces their encumberance.
"If you look through your scope and see your shoe, aim higher."
-- said to me by my 11 year old daughter before going out for hogs 8/13/2011