Economy class is a product. It might vary from airline to airline in some small measure. If it doesn't fit you then you either put up with it or buy something else. It is the same for most products. Many cars are too small for tall people it doesn't mean they have to substitute something more expensive or in restricted supply for those that are too tall.
Do what the wide people have to do and buy two seats. Pay for a more comfortable class of seat. Put up with the discomfort. Try the leg room seat lottery. All of these options are open to you. The problem here is that you don't fit a standard product, and that product is costed on being a standard fit. If you want something that is comfortable and does fit then you are unfortunetaly going to have pay for it along with the people who are too wide, claustrophobic, or choose to travel in a better environment. It may not be your preferred option, it may be unaffordable, it may mean you elect not to travel. Again, the airline is selling a defined product at a set price. If you don't like it buy elsewhere or don't buy at all.
On the subject of exit seats, these would have the same pitch as every other seat if most commercial carriers had they way. That would yield more revenue per aircraft. The fact is that the positioning of doors and legislative requirements mean a few seats have greater legroom. Obviously these seats are very popular and demand for them far outweighs the supply. There are classes of passengers for whom age or physical limitations would normally preclude their being allocated such seats. That still leaves the majority of passengers on a flight qualifying for the allocation. Normally such seats are not allocated prior to check-in, so that staff can ensure they are properly allocated. The earlier you check-in, the better your chance of obtaining such a seat. Obviously this is a bit of a lottery, but you take your chance.
Finally, some airlines have recognized a market for an economy product with greater legroom. They offer this at a premium cost. In reality if all airlines were to increase their legroom to this level of revised seat pitch the price per unit would rise accordingly as the number of seats (available yield) would obviously fall. If you want or need the guaranteed space you are going to have to pay for it. You can't expect something for nothing.