Let me try…
We are not going to switch to the GPL. We use the 2-clause MIT license, which is compatible with it, for the code we write. This decision was made when the project started so the code could be reused in an eventual continuation of the original BeOS. This didn't really happen, but I think projects like Zeta used some of the code. There were some patches for BeOS based on Haiku code as well.
One of the initial goals of the project was to provide an OS to people trying to run (or sell) their proprietary applications written for BeOS. There is one succesful example of this with TuneTracker Systems. For this reason, our point of view about free software is quite different from the FSF one. Have you tried one of the Linux versions they advertise? You will quickly notice that you likely can't connect to Wifi without first installing a "binary blob" firmware for your Wifi adapter. This is why Haiku includes them. We think the most important thing is that people can use the computer, and if there is no other solution than including a binary blob, we go for that.
We also include some proprietary software such as WonderBrush and liblayout (used by Beam and BePDF) in our releases. This is also on purpose: we think there is nothing wrong with non-free software, if that's what people prefer distributing their programs like. Who are we to decide which licence people should use to write their software? And why would we not distribute it if they allow us to do so?
Over time, people found that free and open source software was a good thing, as they tried to use old BeOS software, they saw how having the source makes it much easier to debug and fix things, even after the author has moved to other projects. We even had some success at getting the sources for BeOS software back from some people old backups and open sourced. So I'd say our way to handle things is working very well, and making people do open source in the long term. While we will probably never do well enough to be on the official FSF list, we are not in bad terms with them. We disagree on some things, that's it.
Personally, I think the no-compromise decisions of the FSF is not a good thing. IT is for this reason that a lot of projects are using llvm instead of gcc. While gcc is free software (under the GPL), writing a proprietary plug-in for it is disallowed. What is that free software licence that prevents you from doing whatever you want with the code? Isn't that just as restrictive as proprietary software? The goal of the GPL is to create a separate bubble of software, which never mix with existing proprietary things. Bridging the gap between the two are BSD-licensed (or similar) projects, and there will always be some there, because when a company has a choice between a BSD and a GPL project, they will often take the former, even if they plan to contribute to it or release their code as open source.