Why does this happen?
Is this standard for all TSX's?

 

Yes

 

In my state it's illegal to have both the high beams and fogs on at the same time and assume other states are like this as well so that is probably why it is set like this.

 

illegal to have both high beams and fogs on at the same time? really? what is the reasoning behind this? (not doubting you, genuinely interested in the answer)

I always assumed that it was just counter-intuitive-- if you've ever flashed your high beams into fog, you know what I mean.

 

Having any other light on with the highbeam (with the exception of a momentary switch between low and highbeam or a low intensity running light) is a violation of FMVSS 108 - accordingly fogs and highbeams on at the same time are illegal in all 50 states, the DC and territories

 

The fogs contribute nothing to the driver with your high beams on and you completely screw over any other drivers who happen to approach you.

 

First of all you should only be using your fog lamps in the fog and high beams in fog don't work. So there is no logic for using your fogs and high beams at the same time. Some people especially older folks are sensitive to bright lights at night. So do them a favor and use your lights as intended.