Exactrail does sell through hobby shops at short discount - like Intermountain, Kadee and Red Caboose. Tangent does not.
There is the problem, a short discount. Add in that you have to pay the freight and you are closing in on no discount. That means no profit. No profit means a store will not stock it. Add in a requirement to buy a LARGE minimum amount of their product in a year and that adds up to no sale.
A pity because they are very good products and should be in stores.