Every time there's a story about OSS software being less than perfect, someone always trots this tired crap out. "Oh if it isn't want you want you can just fix it!" That is complete bullshit and you should know it. If you don't, you are hopelessly naive.
First off, most people are not programmers and many do not even have the request problem solving, analytical, and mathematical skills to become one. If you aren't a programmer, you can't just go and fix software. Becoming a programmer isn't magic either, you don't go and read a book and then you are good. It takes years of experience to get proficient, and decades to really master and is something you need to spend a lot of time on. If you think you are some hot-shit programmer and you "picked it up just by reading" and "just do it in your spare time" then guess what? You aren't near as good as you think you are.
Second, even if someone is a programmer they may not have the requisite skills or knowledge to deal with a piece of software. Not all software is created equal, not all problems are the same to solve. Someone might be a programmer who's actually pretty good, but knows about making database code because that's what they do. However if they are trying to implement an algorithm for processing audio they might be lost because they don't understand how that works, it is another set of knowledge.
Finally, even if someone does have the skills, knowledge and experience to do it, maybe they just don't want to spend the time. We all have only so much time to spend in a day, maybe they are not interested in dropping a bunch of time to fix something that is to them just a tool. They'd rather pay to have one that works and spend their time on other shit.
So knock it off with the "oh it is open just do it yourself" crap. That is extremely silly, and you know it.