Why do almost all ASP.NET open source projects require money for copyright removal?

Question

ASP.NET

I've been developing in ASP.NET for over 10 years and I noticed an interesting thing that infuriates me, to be honest.
For some reason, almost all more or less decent open source projects on ASP.NET, in addition to the standard license (GPL, etc.), require "powered by ..." on all screens and ask for money to remove it?
Those. I cannot say that developing an online store in ASP.NET is more difficult or more expensive than in PHP.
And I can't say that they (ASP.NET projects) are better in quality or features than PHP ones - rather the opposite.
But at the same time, the trend is stable.
Examples:
1. Online stores
Top PHP stores do not ask for any money for removal powered by: Magento, OpenCart, PrestaShop, WooCommerce(there are many more stores, but I haven’t looked at the rest)
In the same Presta there is even a checkmark in the admin panel to disable it without having to get into the code.
There are not very many ASP.NET stores. The most famous one is NopCommerce asking 120 bucks for copyright removal. At the same time, in terms of capabilities, the number of additions and documentation (including in Russian), it is very much inferior to the above PHP ones. Next in popularity: Virto Commerce - also requires powered by. There is an even less well-known SmartStore - it seems to just have GPLv3 listed, but it still needs to be checked.
2. Forums
PHP forums are just tons, so I won't even list them.
There are very few ASP.NET ones.
known twoYetAnotherForum.NET is old junk still on webforms and the newer MVCForum.com which is still not really done - both asking for money to remove the copyright.
Where is the logic?
To what extent does such "greed" correspond to open licenses?
I periodically have a desire to fix something in these projects, but the toad is choking. I will try here, do it for free, and then someone will take money for it. And I suspect I'm not the only one. And therefore - such behavior only slows down the development of projects. So why shoot yourself in the foot?

Answer 1

> Why...
Why is a good half of the programs on Zhukveri generally unclear to whom it belongs and under what conditions it is distributed? And for programs on Emax-lisp, on the contrary, the list of copyright holders and the license are always very meticulously designed.
There is such a subculture.
> To what extent does such “greed” correspond to open licenses?
Open licenses are licenses issued to an unlimited number of persons. They have nothing to do with "greed" or "non-greed". There are, for example, a whole bunch of open licenses that generally prohibit you from using the program for free for more than N days, this practice even has a special name - shareware.
Maybe you want to know how the requirement about "powered by ..." corresponds to the concept of a free program? I don't see any contradiction between the attribution requirement and the definition of free software.
Or perhaps you're wondering if such a requirement would conflict with any particular free license—well, the most popular one, the GNU GPL, for example?
If we take its current ( third) version, then I also do not see any contradictions. On the contrary, paragraph "b" of Article 7 expressly allows the requirement of "preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it". This point is often interpreted quite broadly - for example, OnlyOffice'a license requires displaying in the user interface no longer a simple hyperlink, but a graphic logo (if it is technically possible). And by the way, this is another example for you, because its server part is also written in ASP.NET.
The same is true for the GNU Lesser GPL and the GNU Affero GPL.
Moreover, this does not contradict lax free licenses, which are called so because they allow you to wind up any additional prohibitions.
PS [quotes of remarks - from the comments]
> Just the fact that "it happened" I understand. I don't understand why it happened.
And this, I believe, is a question that is still waiting for its researcher - the historian of free software. Considering that I don’t know a single person with such a specialization at all (and you?), I must think that you will not get anything in the foreseeable future except for guesswork.
The format of questions and answers is the most suitable for guesses and versions, but if you are still personally interested in my hypothesis, then I think that the question should be asked the other way around - why is this not accepted outside the ASP.NET subculture - no, Seriously, this sounds like a great way to make money ethically with free software! I suspect that outside of it they simply do not know about such a reception..