So you would welcome a $2600 dollar a year pay cut? Same thing with retailers. Tax deductibility is manifestly fair since we tax profits and shrinkage is a one-for-one reduction in profits. To the extent that stores have to take measures prevent theft, it costs them money. Stores are in a better position to judge how much to pay to reduce shrinkage, which will also reduce profit and sales, than any bureaucrats or bloggers.
Again, your thinking is not correct.
Allowing corporations to deduct theft before taxes is a disincentive to the corporations to enact theft reduction measures, and spreads the burden of the theft to the public taxpayers through reduced payment of taxes by the corporation.
If theft expenses were purely after tax, companies would be more incentivized to reduce theft.