The reason why men are men is because of evolution.  The shape of the human penis is designed as such as to extract sperm out of the vagina.  Subsequently, to ensure fertilization of the ovum, men only have a single orgasm and become flacid.  In addition, unlike women, the male orgasm is tied to a specific event, ejactulation.  If men were to have multiple orgasms, then they would have difficulty with copulating with multiple partners and ensuring the continuation of the species. 

So, to reiterate, males have a single orgams for evolutionary reasons.  The two-fold purpose of it is to ensure insemination, by detering prolonged sex and allowing a male the opportunity to copulate with more than one partner.  Evolution is also the reason why males are able to maintain their senses while having sex, where as women get lost in the moment.  Men are capable of being more alert due to fact that they needed to ensure there were no threats approaching while copulation occurred. 

The art of an orgasm is how to prolong it until you can't hold back anymore.  Then, yes it's worth it.  Also men can have multiple orgasms through a prostate orgasm.  Through normal penile stimulation you aren't limited to one run, however you are typically required a little down time.  It varies based on the man, his physiology, and heightened sexaul interest.  However, some men can immediately get back to business while typically after the first orgasm most men require about five minutes before they can obtain a full erection. 

Hence why I recommend, she deliver a blow job to ejactulation, then you go down on her until you regain your erection.  Then depending on you, you may last anywhere between 5 and 15 minutes giving you ample time to try new positions as well as bring her to orgasm. 

Buying roses and other delectable treats. In Greenland it would be Whale hide. Going on Numerous dates, hours of foreplay, and then possibly if a headache does not happen, you get 3 seconds of pleasure. Really?

buy the way, the new show Ice cold gold, filmed in Greenland where the ice has finally melted after 10,000 years, is really good.

Close, but you're off on a few things.
It's not that men would have had multiple orgasms if not for copulating with different partners.
Women have multiple orgasms because it allows for as much insemination as possible (having multiple male partners).

Men also get lost in the moment, and are very affected by dopamine while copulating. The single orgasm breaks this effect by spiking it, which brings the male back into reality immediately after orgasm.

Males become flaccid to allow for other males to have their "turn".

If the case was to allow for other males to have their "turn" then that could potentially defeat the purpose of copulating in the first place.  Because once another male entered the vagina, the head of the penis would essentially extract any seminal fluid or deteriorate it through excessive friction.  Not only that but with one sexual partner the vagina can easily develop tears, making sex painful.  Multiple partners would be even worse.

Plus your view point doesn't fit with the typical desire for women to have a single partner, where as men are more capable of having multiple partners.  That isn't to suggest you can't have indivuals that fit outside those norms, but I would need some evidence to convince me differently from my opinion.