"they don't have to recuse themselves when voting on tax bills that affect thier company"
That's not entirely accurate, Mucky.  They do have to recuse themselves, and IIRC they did, but there is little accountability to who disputes a recusal _and_ the current system requires unanimous consent for a recusal so that it never has a chance to last.  With two employees in either chamber all it takes is for one to anonymously dispute a recusal of the other for it fail.  That's one of the reasons why I hope to see Grenn's bill to change the procedure gain some traction this session.