I agree, US companies should have better policies, but that would rely on the government enforcing an even playing field (not very libertarian). Otherwise there is no way any single company can stray too far from the pack without seriously damaging their competitiveness.
Maybe something like the government covering 70% of the your away pay (capped, obviously), and giving the company 15% to go toward to whatever they chose (covering you more, hiring a temp, the bottom line, etc.) The size of the company could also be a factor on how large that payment is (the smaller the company, the larger the percentage).