For the record, I'll state that I do not run a startup, nor have I influence in any larger business, so my comments should be read with that in mind. However, the company I work for, does release open source software, and it's licensed under the GPL (or a mixture of GPL and LGPL). If I ran a business, I'd do the same.
The reason for that, is the viral nature of the GPL: it's not friendly towards closed source, which is exactly what I want. If I, as a business, release a piece of code, then I want to benefit from any enhancements others make to it, I want to have the option, to take those modifications, and incorporate them into my version. With the BSD license, I'd be at the mercy of others, they may opt to contribute their changes back, or they may choose not to.
I don't trust most businesses, so I do not want to let them have that option: if they use my open source code, I want to have their modifications too, so we can mutually benefit.
Thus, for me, freedom of the code is more important.