Henry,
I agree with your point of view, and at the moment that I decided to take each of these exams I was working with the technology of the exam. But this wasn't the only reason I did that, I've realized that the knowledge that I've obtained in each of the certifications made me a better
Java programmer, because I could progressively see the whole picture of the Java stack.
Another great thing of doing that was that every technology I got to work after I did the certifications had something in common or have concepts that I could benefit from the knowledge obtained while studying for the certifications. In other words, even the technology not being the same, many frameworks benefits themselves of concepts created in Java official specifications or have concepts that follow the same thought line. An example of it is the transaction model of Spring, its based on the EJB one. Another example is with Servlets, Filters, Listeners, etc, I got to work with many frameworks like
Struts, VRaptor, Spring,
JSF, Velocity, DWR, etc and each of them are somehow based on the Java-web technologies.
That's a good thing, I guess. Now I'm studying for the JPA exam and that requires me to study transactions in a deepest level of detail again and also the many aspects related to persistence in a Java application with persistence enabled. Even the certifications doesn't meaning anything if the knowledge is not properly obtained (I've seen many dumping questions instead of really learning the subject), it is a good path for Java programmers that may decided to start from scratch to learn a lot of things that may be part of their reality for the next years. Obviously this will require more study on each subject the programmer decides to learn about, but the basis will be there supporting his studies.
About what you said related to keep studying the subjects that I have obtained certifications in order to become a specialist or something like that in that area, sounds good but has it's considerations. I'll much probably not work with EJB so soon, but I do want to study some concepts and areas of it again because I feel that these are present during my days as a Java programmer. The same is true about Java the language itself, the Java web technologies and also with JPA. I think that everything I have learned so far is useful and what is not, is getting down in my brain index, now I'm capable to see what I should study instead of just doing certifications without a clear goal, but once I got so far I'm going to do the architect one in order to help me understand the skills needed by a Java architect.
After that I plan to keep studying what I've learned, others frameworks and technologies, maybe get deep in the JVM world and other languages.