You have some guarantees of access to the present source code (and as jdjb points out, not necessarily), but you're certainly not guaranteed access to changes made in the future by that or other parties like the GPL does. That's the whole point of copyleft and why I prefer it, I don't want to worry if I'll be able to access the features and fixes that will be made by others or if I will be left in the dust. And fair's fair, if you benefited from the work made by others then it's only fair to them to benefit from yours.

Maybe I'm mistaken, but I have the feeling that many -of course, not all and I'm not saying that you do- think that their precious code is so amazing and it will give so much competitive advantage that they need to leave open the option for a closed source version that will make them rich, and that's why they defend "freer" licenses very passionately. Newsflash, it almost surely -like 99,99%- won't happen.

This is completely wrong. Purchasing a product that contains code licensed under the BSD license does not ensure you get access to the source (unmodified or otherwise). It is the biggest difference between the GPL and BSD license.

All the BSD license ensures is that if they distribute the code they have to retain things like author retribution.

Restricts what freedom? If there indeed is a meaningful restriction, you should be able to articulate it in words.

The freedom to profit from code in the same way as the author. Oracle, for one, has done marvelous things in ensuring that their JVM is the only one that people use by GPLing it and convincing IBM to stop contributing to the more open Apache Harmony project. Additionally, the same enterprise can do things with MySQL that no other vendor can, again putting other entities at a distinct disadvantage. The GPL is very weaponizeable if you want to ensure competitors are always a step behind you.

I don't know about the JVM, but what you mention about MySQL has to do not strictly with the GPL but with it being dual licensed (GPL and propietary) and as a result many Linux distributions like Red Hat, OpenSUSE, Fedora and Arch decided to make MariaDB -which is only GPL, compatible with MySQL and has more features- the default and it's readily available in most -if not all- distros, Windows and Mac OS X. So I would take the part of "competitors always a step behind you" with a very big grain of salt.

How is Apache Harmony more open? Easier to get in extensions without going through all the committees? You can do that with a fork of the OpenJDK too, nothing in the GPL preventing that.

As for MySQL, I don't see how the existence of a proprietary version of MySQL is somehow the GPL's fault. The users would be even more at a disadvantage if the proprietary version was the only one that existed and there was no free version, so the existence of the GPL version is a net benefit for everyone.

Not that it's a particularly good idea to buy a proprietary license or even contribute code to Oracle. PostgreSQL will treat you much more fairly. It doesn't require copyright attribution from their contributors, it's governed by a 501(c)(3) charity in the US and a similar non-profit in the EU rather than a company that only looks out for itself.

There is nothing wrong with making a profit with software, but signing an expensive restrictive EULA for a database is just a bad deal, whether you're a small startup or a major corporation.

The freedom to deprive end-users the same rights*[1] the distributor got, of course.

[1] The right to view the source and make changes as you see fit.

The freedom to modify the code w/out having to share those modifications.

In essence it "restricts" your ability to profit from others effort.

It doesn't even do that. I profit plenty from others' GPL-licensed effort. The difference is I don't feel entitled to restrict others from profiting from the effort that went into creating the combined work.

There is no such restriction. Freedom 3 is just that, a freedom, not a duty to release your changes to the public.

All it does is ensure that your users had the same freedoms that you did.