This question is asking about great modern philosophers, but is it on-topic? Is questions asking for great modern shaikhs, Muftis, Huffazz and so on on-topic as-well?
2 Answers
I would generally say that it is okay, so long as the question is written in a reasonable scope and is otherwise constructive in the StackExchange model (I closed the linked question, for example, because it was a non-constructive list question with no real focus, not because I felt it was off-topic).
Just as ilm al-rijal was a necessary discipline for determining the authenticity of hadith during the early days of Islamic scholarship, so too is it important to understand the men who claim (or are proclaimed) to represent Islam now. As any fatwa, for example, is only as useful as the mufti who announces it, one must know whether or not it comes from a reliable source.
As such, I feel that questions that directly regard modern scholars (and philosophers, etc.) are entirely on-topic, insofar as the questions relate to their ability and qualifications to represent and teach Islam.
That question is rightly closed as being about Muslims, not Islam. As such, it's not a good fit to our site.