Whether she enjoys sex or not does not really matter.
Because meeting your spouse's ENs works better if it's at least pleasant. Unpleasantness erodes POJA like nobody's business.
Sure, if SF is the bottom need for your wife, she may not want to 'get much out of it' - you don't have to feel obliged to make sure she has multiple earth-shattering orgasms every time.
On the other hand, if you're just grinding away on her, sweaty, unshaven, unshowered, not having brushed your teeth this week, without regard for that knee she sprained walking the dog and the fact that she hates someone squeezing her nipples, saying 'oh, it's not really meant to do anything for you' is extremely callous. (This, dear folks, is NOT a true story from my life, but it is a conglomeration of true factoids.)
And that's assuming SF is not important to her. Many people here on this board have SF maybe not as a top need, but in the top 5, and for them, meeting just the spouse's needs leads to unfulfilled needs for themselves. And to just guess the H has it as #1 and the wife as #9 is pretty naive.
And yeah, I think the same goes with all ENs - you have to make sure that the person meeting your needs has a somewhat easy time of it.
No snide comments about your mother when you're just talking to me because I have a need for conversation.
No throwing fast balls at your head when you're just coming to dodgeball training because of my RC needs.
No leaving cat's vomit lying around because you'll be sweeping the floor tomorrow trying to meet my DS needs.
No quitting my day job when you're only sticking around in your awful job to meet my FS needs.
Me not putting on a migraine-inducing perfume if you try to cuddle with me to meet my Affection needs.
No undercutting you in front of the kids when you try to step up and meet the FC need I have.
No saying 'what do you know about it?!' when you're just giving me a compliment to meet my Admiration needs.
No tearing into you when your attempts to meet my H&O needs bring up some things I don't like.
And no saying 'oh, I'd forgotten what your chin looked like' when you finally shave on behalf of my PA needs.
Yes, fulfilling your spouse's ENs is a lot of work, but it shouldn't be made extra complicated by having to fight through layers of distaste to do it. And it should be a team effort, not an exam where you throw the most difficult situations at people and see whether they fail or not.
POJA, AverageGuy.