I came across this sentence while reading Wikipedia and the second occurrence of "continuum" stood out to me as totally wrong since a continuum is specifically a range which can be divided into an unlimited number of possibilities.

"Some linguists consider the rough/soft continuum more accurate than the male/female continuum.

So what is the best word to use here to differentiate the very limited number of possibilities?

EDIT

I'm genuinely surprised that so many people find "continuum" a good way to describe a choice between "male" and "female". As a programmer I can best clarify with a programming analogy:

• To represent the rough/soft continuum I would use a float type
• To represent the male/female choice I would use an enum or a bool type

(apologies to the non-programmers who may be baffled by this jargon)

EDIT 2

I think I need to clarify what I was and was not asking:

• I was not asking about semantics or biology or gender identity regarding the existence of points between "male" and "female". I agree such points exist.
• I was not asking about semantics or linguistics regarding the continuous range of the subject of the linguists' consideration. I agree that what they are considering is a continuum.
• I am asking about English Language & Usage regarding the choice of words of the writer of this sentence which in my opinion poorly contrasts "continuum" to "continuum" in a comparison.

Let me rephrase the sentence the way I read it:

Linguists generally hold that there is an option between male style and female style, but some linguists consider this inaccurate and instead hold that there is a free range between rough style and soft style.

Whereas it seems to me that some answerers and commenters have read it this way:

All linguists hold that there is a free range of style and while this range is generally referred to as a "male/female continuum", some linguists consider that calling it a "rough/soft" continuum is more accurate.

To me the first reading seems natural and second reading seems strange. The second reading seems to trust that the writer has flawless skills in English language expression and definitely wrote what he intended. Alternatively the second reading would make sense if there existed a technical linguistic term "the male/female continuum".

Since I can find no use of such a term used by linguists besides this Wikipedia article (but I can find it in other fields such as gender identity), I read it as a sentence from a writer who knew what he was thinking but due to poor word choice did not write what he intended.