Libido Mismatch - Or Something Deeper?

There is a certain thinking that most sexless marriages come from a huge libido mismatch in a relationship. This is the thinking that your libido is your natural sex drive and it can be average, higher than most, or lover than most. There is evidence that some people do have physical differences that will affect the amount of sex they desire, but is this just a convenient excuse to blame genetics or god rather than psychological and general aspects of your relationship?

Let's look at what is libido first. (From the libido page on wikipedia)

Libido refers to a person's sex drive or desire for sexual activity. The desire for sex is an aspect of a person's sexuality, but varies enormously from one person to another, and it also varies depending on circumstances at a particular time. A person who has extremely frequent or a suddenly increased sex drive may be experiencing hypersexuality. Sex drive has usually biological, psychological, and social components. Biologically, levels of hormones such as testosterone are believed to affect sex drive; social factors, such as work and family, also have an impact; as do internal psychological factors, like personality and stress. There is no measure of what is a healthy level for sex. Sex drive may be affected by medical conditions, medications, lifestyle and relationship issues.
There is no necessary correlation between the desire for sex and actual sexual activity. For example, a person may have a desire for sex but not have the opportunity to act on that desire, or may on personal, moral or religious reasons refrain from acting on the urge. Psychologically, a person's urge can be repressed or sublimated. On the other hand, a person can engage in sexual activity without an actual desire for it.

So what we can learn form this is that the libido is not JUST a physical genetic thing. It is not set in stone either, your libido can fluctuate based on a variety of different factors. This is important because it means that mismatched libidos of course DO exist, but it does not mean they can always be mismatched. It also does indicate that there might always be some genetic disparity but it would be foolish to think this would rule over all the other factors.

So mismatched libidos is could be considered a state at a particular time where one partners libido is very low and the others is normal or much higher. This is a transient thing that can change, but it does not mean it can change on its own. Libido could stay low if the factors that cause these things were to continue to put pressure on their sexual desire such as resentments and of course all the other physical and mental aspects.