Wiki, and TheLiterature? (and all manner of casual programming conversation) is chock full of claims like "Language X is simpler (more complex) than language Y, because..." Many such claims are based on rather trivial metrics, like number of keywords, etc.
What is a meaningful definition of simplicity/complexity?
Ease with which a novice can write his own HelloWorld program?
Ease with which a novice can become a competent programmer in the language?
Ease with which a novice can become an expert in the language?
Ease of implementation of the language?
Ease of extension/tool development?
Ease of developing simple applications (glue code, CrudScreens)
(Relative) Ease of developing difficult applications
Ease of developing applications in the language's intended domain area?
Ease of developing applications outside the language's intended domain area?
And various metrics which get bandied about
Size/complexity of grammar (number of rules of BNF, presence of ambiguities, etc.)
Number of keywords or "special forms"
Size of the standard library
Comprehensiveness of standard library
Number of "kludges" in the language definition (all mature languages have quite a few, it seems)
Presence of any smaller "subsets" of the language which are useful (does the EightyTwentyRule apply to the language)?
Number of ForDummies books, training courses, college courses, etc. available for the language
Quality of implementations/tools/environments
Way programs are entered, integration with environment