You are absolutely right! Xilisoft iPhone Ringtone Maker does exactly what its names suggests: this tool has the only purpose of creating ringtones for you iPhone. It is good it supports importing not only audio but video files as well. Not only that, it allows a wide range of media formats, which comprises the most popular ones.
The application has an extremely user-friendly interface. All you need to do is load the source file, which can be done via menu or a drag-and-drop operation. The next step is selecting the segment you want to keep. For this purpose, you can either use the corresponding buttons or simply drag the handles to the desired position, and, luckily, there is the possibility of previewing the results. It is a pity that, unlike other similar software, the only effects available are Fade in and Fade out plus volume adjustment. When your ringtone is ready, you can transfer it directly to iTunes or your phone, and it can also be saved to your computer in M3R format.
In a nutshell, Xilisoft iPhone Ringtone Maker is an easy-to-use application with a very specific purpose. Regrettably, its trial version can only export up tones of up to 10 seconds. Personally, I would not spend any money in a product like this one as there are free sound editors that allow doing the same at no cost. However, I would agree with the objection that creating ringtones with a general-purpose editor is definitely more difficult.