It's just that "synthetics" doesn't really tell me anything about what in particular is causing the problem.
With recent advances in technology, things seem to just keep getting better and better. Tractors now have giant irrigation systems that roll over the entire fields automatically, with ion specific sensors detecting the levels of each macro nutrient, and providing only what is necessary. It just seems to me that the people who want to hold all this back generally only know whether "chemicals" are being used or not.
There are 2 major types of synthetic formulas commonly used. Products like miracle grow, peters, and jack's classic are all based on urea for N, and feed nitrifying bacteria. Hydroponic formulas source the majority of N as nitrate, which is what the nitrifying bacteria produce. It's counter-intuitive to feed a living soil with nitrate salts, and also counter-intuitive to use urea based formulas in inert, dead media.
Per capita, water pollution has been going down in the last few decades as phosphorous runoff has dropped dramatically.
I'm not against organics, but as long as there's a growing population, we will need to produce a certain amount of crops. Doing that organically means going back hundreds of years to crop rotation. That means having 3 fields for every one producing field. I just can't see how people automatically assume that something being "organically" grown makes it magically taste better, and be "healthier". It's completely made up, just like flushing! "hey, your bud looks awesome, but i prefer quality so mine is organic, thus higher quality". bull!