You cannot buy software these days. You have to spend a fortune hiring someone to create program to meed your specific need, show you how to use it, and then make modifications as necessary.
1/ Dev: Stop hiring whiteboard coders.
2/ Product: Stop hiring MBA's who can tell you a lot about strategies and nothing about building solutions.
Long story short, fix the hiring process in tech and you'll see a much better outcome. Customers and Users ain't care about my GPA, they want pretty solutions. Hire people who know how to build nice products, not how to sort a linked list in 2 minutes on a whiteboard under pressure. Google started that trend back in 2000 and everyone followed... Guess what, Google products have always been the worst products out there in terms of User Experience.
I disagree, you can buy general-purpose software. However, these days general-purpose does not give you a competitive edge.
Business is about having a competitive edge. Today, to do that, you need software beyond whatever everyone else can buy.
Yes that CRM tool might work in general, but does it do everything you need, exactly how you need it to be done? Very unlikely.
Also, what is a fortune? A few tens of thousands of dollars?
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To answer your question as to why bad software happens...
If the developers are not actively using the software it's going to be really bad.
Even if they are, if the business prioritizes number of features over quality of features, the software is going to be bad: your devs can only do so much.
Even if your devs are using your product and they have the time to make the features great, if they are not motivated your software is going to be bad: why would your developers care to make something better when they realize it can be better if they just don't care?
Obviously it isn't all on the developers: but it's not all up to management, either. It turns out it's really hard to check all three of these boxes off, so most software is sub-par.
Even great developers who are a part of a great company have created not-so-great software.
It is easy to add stuff, almost impossible to remove stuff.
People are change-averse, which gets in the way of continuous improvement. (They stick with Python 2, platforms like AOL IM, Skype, and HipChat seem to reach a certain level and then slowly deteriorate.)
It would also help to make programming more accessible to non-programmers.
I think to make improvements would be forcing every software developer to read Design of Everyday things before writing a line of code.
In the words of Sherlock Holmes 'You see, but you don't observe'
Btw i'm not a designer, someone who tries to write non shitty simple software.
Correct, you have to rent it. Which, IMHO, is a tragedy. It's turning tools and craftspeople into walled fiefdoms with fickle landlords and helpless serfs.
We should keep in mind that most software replace tasks that are too complex or impossible for a human to do!
At the end of the day if you order an ice-cream, ketchup, and anchovy pie and it tastes bad it is your fault: but who would want to make such a thing, anyway?