I am not a lawyer, but I fear the situation descrbed is not against the GPL. But I'll let you discuss on that, I really don't know.
As far as I remember, a library should be put under the LGPL and not the GPL. Because putting the lib under the GPL would restrict the freedom to use it, as you point out. Thus the LGPL was designed to allow such a use. Anyone knows more details?
http://www.gnu.org/philosophy/why-not-lgpl.html
That proves you wrong.
Well, I would say, that it is already against the spirit of free software to publish a library under the GPL and not the LGPL.
Actually,
<quote from web page> Which license is best for a given library is a matter of strategy, and it depends on the details of the situation. At present, most GNU libraries are covered by the Library GPL, and that means we are using only one of these two strategies, neglecting the other. So we are now seeking more libraries to release under the ordinary GPL.
Proprietary software developers have the advantage of money; free software developers need to make advantages for each other. Using the ordinary GPL for a library gives free software developers an advantage over proprietary developers: a library that they can use, while proprietary developers cannot use it.
Using the ordinary GPL is not advantageous for every library. There are reasons that can make it better to use the Library GPL in certain cases. The most common case is when a free library's features are readily available for proprietary software through other alternative libraries. In that case, the library cannot give free software any particular advantage, so it is better to use the Library GPL for that library.
This is why we used the Library GPL for the GNU C library. After all, there are plenty of other C libraries; using the GPL for ours would have driven proprietary software developers to use another--no problem for them, only for us.
However, when a library provides a significant unique capability, like GNU Readline, that's a horse of a different color. The Readline library implements input editing and history for interactive programs, and that's a facility not generally available elsewhere. Releasing it under the GPL and limiting its use to free programs gives our community a real boost. At least one application program is free software today specifically because that was necessary for using Readline.
[...] </quote from web page>