Because an ongoing sexual relationship requires a fair degree of vulnerability and trust, and at some point, we have been convinced that that trust has been misplaced.
Same for every human being regardless of libido. You seem to feel that LLs are somehow different in this respect. Weird that you find yourself unique in that respect.
Because any sickness, fatigue, or outright injury is treated as nothing more than another excuse to get out of sex.
Most sickness, fatigue, and outright injury doesn’t prevent people from going to work, taking care of the kids, seeing to the household chores, etc. It seems as though sex, and therefore the partner you used to enjoy it with, is always the first and easiest priority to get bumped. Why is that?
Because any physical contact or show of affection is treated as an invitation to escalate further. It was mutually so in the beginning, why did you change the rules?
Because our partners require constant validation of their sexual worthiness from us, and we get tired of being bedpost therapists. And you’re exactly the same, or would be if we stopped finding you sexually attractive and refused your attempts at physical affection. Let's all try that for a few days and see what develops.
Because our partners are selfish in bed, and even when they're "selfless," it's about preserving their self-image as a "great lover" than any desire to actually be one.
It’s really not any fun to have sex with someone who requires several days advance notice, rules out anything which varies from missionary and requires a two hour warm-up, either, but we’re game because we love you, even if it is a pain in the ass to help you get excited about sex.
Because when we say "no," we're made to feel like shit for it.
And we’re made to feel like shit for seeking sex with our partner. Let’s call it even.
Because when we say "yes," we're made to feel like shit for not putting more effort into the sex we didn't want. We’re made to feel like shit if we half-ass other couples activities, so we know how that goes.
Because our partners decide it's a "medical" problem, and then all but order us to start changing up medications we've selected after a long dance of dealing with unpleasant side effects to find a manageable one, start using blue pills that don't fix the underlying issues and don't mix with our other medical conditions, or even worse, take controlled substances with potentially horrendous side effects prescribed off-label by quack "hormone therapy" clinics.
If a side effect of a medicine turns you into a sibling instead of a spouse, and there are alternatives, seems like it’s in everyone’s best interest to try another.
Because our partners have let themselves go, and when they decide to improve, get pissy that a few diet sodas and thirty minutes on the elliptical don't lead to an all-night sex marathon.
If this is coming from someone in perfect shape: good point.