If they had managed their patents with the aggressiveness that we see nowadays, early aviation development might have been stalled for a decade.
It is amazing what they had to invent and discover to get from the then-current state of the art to a practical flying machine. To give a few specific examples: invent modern propeller theory, dispel long-revered aerodynamic experiment results (Smeaton's coefficient and Lilienthal's airfoil performance data), manufacture a sufficiently lightweight and powerful engine (with significant help on this front from a mechanic they employed for their bicycle business), and pretty much the only effective aircraft control schemes at the time (when people did not even think control was that important!). I am probably missing a few things but each of the points I listed required lots of effort and iteration.
They deserved much more than they got, and tried to use patents for its intended legal purpose. People just didn't play fair by the Wright brothers' estimation. One could speculate that they maliciously and/or selfishly held back innovation, but if you look at their character throughout their journey of invention it seems more likely that they decided to engage unscrupulous enemies, which unfortunately absorbed a lot of their time.
They demonstrated integrity. Inventors all over the world were chomping at the bit of flight by making hops and such, but no one could make a practical flying machine. While others would grandstand on small successes, the Wright brothers focused only on the ultimate end goal of a practical flying machine. They did not make public demonstrations, even though they were far ahead of all others. A small number of people witnessed their progress, and word would spread slowly. But since they were not overtly public about this great progress people doubted them and even accused them of being frauds. This did not deter them, and they continued with their work. The truth was finally revealed to the whole world when they made demonstrations in France, having completed a practical flying machine. It was utterly sensational all around the world, amplified by the fact that they had been highly doubted by prominent figures. These prominent public detractors promptly made public apologies.
In my opinion, the Wright brothers are the greatest inventors / founders in human history. Their biographies are definitely worth a read. My favorites are the ones by David McCullough and Peter Jakab.
From the letter we can see that they did not expect to succeed but only hoped to contribute. From what I've read they really got a rude awakening to the ways of the business world after they invented something of significant value. I am in the odd position of agreeing with you and also thinking they deserved the patent and everything they could get from it. It was not a trivial achievement and involved a number of unique innovations and challenges to the published wisdom.
The Wrights also had to fight with the Smithsonian over their historical legacy, with the result that the original Flyer was displayed in London's Science Museum for many years, where its significance was properly recognized.