Why are agricultural subsidies bad? Good question! Sometimes it helps to think of people instead of countries. If you're a food consumer in a rich country (if?), subsidies in rich countries are bad because you pay more in high taxes than you get in cheaper food (I've seen estimates of around $200 per person per year for Germans). If you're a farmer in a poor country, they're bad because they lower the price you get for your crops, which makes you poorer. And since farmers in poor countries make, oh, $2/day or so, that really, really hurts.
If you're a (probably urban) food consumer in a poor country, agricultural subsidies make food cheaper, which is good. And if you're a farmer in a rich country, they make you a lot richer (technically, it makes whoever owns farmland richer, but that's another story).
But this leads to another question: what are people in poor countries supposed to do? How do poor countries become less poor? I heard Paul Krugman on the radio a couple days ago talking about how in the 1970s development economics was an especially depressing (he should have said dismal) field, because the most recent success story was Japan, in the late 1800s!
I think generally countries in Europe became wealthier when agricultural productivity increased (the Dark Ages saw the invention of crop rotation, water wheels, etc) and not everybody had to be a farmer to eat. People could be craftsmen, merchants, teachers, etc.
Maybe poor agricultural countries need that stage? Is it like setting the minimum wage too high, and telling the workers priced out of the market that they're better off not working anyway?
Farmers in poor countries often suffer under price controls. Farmers are required to sell their crops to the government below the market price, and the government (the corrupt dictator and his tribe) sells at the international price, pocketing the difference. Ending rich country agricultural subsidies might just make only dictators richer in some poor countries.
Since the 1970s countries like South Korea, Singapore, Taiwan, and Hong Kong have done pretty well with what's called export-led growth (countries that tried import substitution, like India, have had poor, and in some cases zero economic growth since the end of the colonial period).
So yeah, if people in Senegal got out of the farming business, and started making all the cheap plastic stuff that's made in China, they'd be all set. What's stopping them? Probably corrupt governments and a lack of entrepreneurs, but I don't really know.
