I suggest that anyone who complains about having to learn something not expect a long lived and exciting career in the computing industry.
I know PHP is very powerful and very quick. I also see the direction of PHP being influenced by the capabilites of Java. I.e., PHP seems to be getting more "Java like". I see OO capabilites are growing in to PHP, which simply leaves room for some of the same mistakes that can be made in C++ that gave rise to Java in the first place, mainly the mixing of structured code and OO code.
JSP is meant as an access point for Java functionality for web pages. It allows the server side folks to develop robust applications (tha can work in higly scalable systems such as application servers using EJBs) that can be accessed by the web programmer from a simple JSP tag. To get the most out of this, it often means that the HTML person has no clue what the java code actually does. The beauty is, they don't have to.
So the problem is which aspects should you compare, and what is YOUR need? Are you making a small to medium size site on your own? Or are you managing an enterprise level system with web access that is being developed by a team of over 30 developers???
If you say the former, then I would say don't waste your time or clutter up your resume with things like Java. You can be happily employed out of your spare bedroom for a long time. If you are looking into the latter, then the Java model is your ticket. I don't even think of MS ASPs as an optiong, because I like my systems to run on stable platforms. But that's just a personal preference.
Make sure you are comparing apples to apples.
Chris