Hmm, not sure
Slow running is mostly a non-issue for me, since I finally got WP SuperCache working right. Whenever I post a new article, or someone comments, the relevant pages are regenerated. Everyone after that gets served a static, compressed page.
As for development time, first versions are fast as hell, with incredibly low overhead compared to Java. (Yes, you can write lightweight Java without a framework, but I've never seen anyone do it.)
I completely agree that maintenance is important enough to disqualify a language or technique if it makes it hard to maintain. But if it's written well, you don't have to question what it's doing. The corollary is that if you have to question what it's doing, the first version wasn't written well and needs to be refactored.
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Drew