Which side of paradise?

Upon finishing "This Side of Paradise" by F. Scott Fitzgerald, there are certain themes that Fitzgerald throws at the reader that warrant further thought.
At the conclusion of the novel, Amory (protagonist) asserts that the intelligent women he meets through the course of his life are all hampered by gawking suitors and the need to 'come out' in society, and marriage.
Eleanor, one such woman with which Amory associates, at one point laments,

"Rotton, rotten old world ... oh, why am I a girl? Why am I not a stupid --? Look at you; you're stupider than I am ... you can play around with girls without being involved in meshes of sentiment, and you can do anything and be justified- and here am I with the brains to do everything, yet tied to the sinking ship of future matrimony. "

This first hint at the restrictions of marriage, which is somewhat dissolved in current society, melts into Amory's final conclusions about the good ol' "ball and chain," where his reasoning is thus:
Well-educated man marries. No matter his social philosophy, his job is to "provide and hold fast." He is resigned to life's windowless treadmill. He is no longer a help to society. This well-educated man becomes "spiritually married."
Sidenote: The "spiritually unmarried" are men whose wives have no social ambition, the ones who fell off the treadmill, the congressmen you can't bribe, the presidents who aren't politicians, etc.
So, the spiritually married man uses society as is, in all of its follies and weaknesses, to get ahead at any cost. The smarter married man can rise in the current system, and sees no reason to change it, because with its flaws he is getting ahead.
The unmarried man "seeks for new systems that will control or counteract human nature." His struggle is to guide and control life. Essentially, progress strives when men do not settle into the hamster-wheel of life's systems.
Now, Amory (Fitzgerald) takes this further into an argument for socialism, but stopping here and looking at the restrictions of the marital structure and what that yields, even today, is fascinating. For instance; how many college students take progressive statuses until settling down into conservative life, two children, white picket fence, puppy?
The phrase "getting comfy" was born from couples who disregard even physical upkeep due to the acceptance of their significant other.
Something about human nature leads to ceasing to produce anything except children and paychecks when we pair-off.
Perhaps there exists some grander feeling that can not be understood until coupled; and indeed, even early relationships have lead to a certain laziness and desire to spend every waking moment with one single person. Biology supports a natural urge to reproduce for the furthering of the race. So as animals, it makes sense. But this lull is still so hard to avoid as highly-educated (or simply educated) beings.
Personally, I fall victim to an occasional relationship desire, but at the conclusion of every single one, breathe a sigh of relief and delve into projects, both physical and mental, cast aside while under the veil of 'love' or whatever attack form it takes.
My Amory conclusion is less a conclusion than a form of questions: Solo is more productive, but how is one to avoid the relationship pull? Can sex be platonic to take care of urges while releasing one unscathed? Do we need partnership other than sex (since sex seems to be the biological necessity)? If one resolves to forever be a progressive thinker, must he/she also resolve to never be tied to another, at least in society's formal mode?
Honestly, the answer to the latter may be yes.