It is tolerated because each country has different industries and priorities that they want to protect. What good would there be to want equal tariffs on something that is barely profitable? This is the problem with things like chemicals and agriculture.
So for example, though we export more chemicals than electronics, the margin on chemicals is shit compared to electronics. One has net margins of maybe 10-15% while the other is around 40-50%.
For other nations however, they may not have tech like we do. So instead they tariff stuff they can actually make. Maybe that is chemicals. That way they can give their industries an advantage similar to how we tariff Chinese tech to give ours a boost. Almost all countries do this. They try to protect the things they value most. Tit for tat on similar items wouldn't make sense.
As for why we dont have generic drug factories... thats obvious. It has nothing to do with trade. They are not profitable. Because the minute any generic becomes profitable, someone else will jump in and pummel margin and it will be a race to the bottom. No idiot is going to build a business on something they cannot patent unless its micro size labs.
So if you want to see more generics made here, what you need to do is lobby to make it easier to open small drug manufacturing plants run by ma and pa. Those guys will not mind the smaller margins. They can probably survive on smaller volume as well. Problem here however... good luck keeping them safe. Ma and pa are notorious for cutting corners and monitoring them would cost an inordinate amout of money. You can try to leave it to customers to decide... problem with that is some drugs are killers.
I am actually for making it easier to build micro businesses. I would just make it a buyer beware sort of thing. No different than us here buying from UGL. In time we developed ways to test products and we coalesce around known sources. But how many people were hurt or ripped off along the way? How long did it take? Bottom line, no big business is going to make these generics. Its not worth it and its rife with risk.