Thanks for the answer, I missed that paragraph. It seems quite disconcerting to me that the average question in the Java tag has been rated negatively the last 4 years. I'm curious as to the specific reason for this downward trend, which isn't reflected in most of the other languages.

One thing that comes to mind for the three which exhibit these patterns, is that they're high volume, slow moving ecosystems. Given the SO community's high penchant for closing questions as duplicates, I wonder if we're just at the point where these languages have exhausted their supply of "sufficiently-unique-and-not-homeworky questions for SO".

Hey, I was thinking about writing something like that in the analysis. I finally decided not to do this because languages develop over time. I'm not a user of Java/HTML/Pascal/PHP but I use SQL quite frequently and in my opinion it is possible to ask a well defined question that did not appear before, at least for some "dialects" (if I name it correctly) like TSQL or Oracle SQL. Maybe if those "dialects" were investigated, their trends would not be downward.