99.9%? That's just insane. You're saying that all the games developers never play their own games?
How about people writing languages, compilers etc. You don't think they use them??
I'd say the majority of open source software is written for yourself rather than others. People contribute the most when they are using that software.
You don't have to be the only customer/user of your software, but it helps to be a customer/user of your own software. That's what I mean by writing for yourself.
I'm saying that the ERP, accounting, banking, claims processing, ecommerce, order entry, scientific, etc., etc., etc. software they work on is for someone else. They dwarf those working on games, compilers, and open source.
I think there's a difference between an engineer working for someone, and the person making the product decision. If you're a developer for a software company building accounting software, and you don't have much use for accounting software personally, you're probably fine. But if you're defining the product, you're much better off if you've been a user of accounting software in the past.
How about people writing languages, compilers etc. You don't think they use them??
I'd say the majority of open source software is written for yourself rather than others. People contribute the most when they are using that software.
You don't have to be the only customer/user of your software, but it helps to be a customer/user of your own software. That's what I mean by writing for yourself.