The 12 practices of XP are not XP any more than a finger is not the thing that it is pointing to. XP is intended to be a minimal set of practices that generate a method. Rather than specify a method (which will dependent upon circumstances), XP specifies a set of practices which will hopefully help you discover the method.
Having said that, if you are not doing the 12 practices, then you are not doing XP. You are doing something else. It's totally fine to do something else, but it is not XP. It may have been inspired by XP. That's also really great. But it is not XP.
This is important because people talk about their experiences with XP and it is difficult to determine if their success (or lack thereof) is actually due to XP, or other factors. Do the 12 practices actually generate a method? Does it happen all the time? Is there something you have to do to get it to generate the method? Is the method always the same? There are many, many question.
For most people, those questions are boring because they are not actually interested in XP. They are interested in being successful on the projects. This is a very understandable position to be in! However, it is frustrating for people who are interested in XP ;-)
Having said that, if you are not doing the 12 practices, then you are not doing XP. You are doing something else. It's totally fine to do something else, but it is not XP. It may have been inspired by XP. That's also really great. But it is not XP.
This is important because people talk about their experiences with XP and it is difficult to determine if their success (or lack thereof) is actually due to XP, or other factors. Do the 12 practices actually generate a method? Does it happen all the time? Is there something you have to do to get it to generate the method? Is the method always the same? There are many, many question.
For most people, those questions are boring because they are not actually interested in XP. They are interested in being successful on the projects. This is a very understandable position to be in! However, it is frustrating for people who are interested in XP ;-)