The Lesser General Public License is only a half-hearted Free Software license. We believe it encourages vendors to take from the community without giving anything back. If we had used it we could no longer sell commercial licenses for Qt. These license sales are today funding the development of Qt and thus benefit the open source community. We like the idea that commercial developers can fund development while open source developers can contribute code.
Fewer licenses make for easier understanding with the community and our customers.
Not at all. Trolltech's business model has always been to provide high quality tools to both commercial and freeware developers. This is a continuation of that model. When used according to the terms of the GPL, there are no royalties. All other usage is according to commercial agreements, which includes royalty arrangements or any other agreement between Trolltech and the commercial vendor.