How it started:

"In all cases of masturbation circumcision is undoubtedly the physician's closest friend and ally... To obtain the best results one must cut away enough skin and mucous membrane to rather put it on the stretch when erections come later. There must be no play in the skin after the wound has thoroughly healed, but it must fit tightly over the penis, for should there be any play the patient will be found to readily resume his practice, not begrudging the time and extra energy required to produce the orgasm. It is true, however, that the longer it takes to have an orgasm, the less frequently it will be attempted, consequently the greater the benefit gained... "

E.J.Spratling, Masturbation in the Adult, Medical Record, vol. 24. (1895): pp. 442-443.

70% of infant circs today are still performed without adequate (or any) anesthetic.
Circumcision has a negative impact on society as a whole, including: attitudes towards pain, control of female sexuality,  reduced empathy, anti-social behaviours, male violence - American homicides, domestic violence, rape and warfare  are 8 times that of the European community.

http://www.circumcision.org/impact.htm

Why it continues:

If you're a cosmetics company, you too can order an infant foreskin on the internet. 

http://ccr.coriell.org/Sections/Search/Search.aspx?PgId=165&q=foreskin

Tissue harvesting for fun and profit!  For the doctors and corporations, anyway.  The actual "donor" gets nothing but a penile reduction surgery against his will. This is organ harvesting plain and simple

Men have no legal recourse against their attackers. Circumcision is most definitely a gross attack against its victim. All are left with a severely altered body, Many with a lifelong sense of being violated on the most personal level, and no recourse at all.

A few things lost: the list is longer but CM won't let you type that much!:

Nerve Endings
Nerve Endings transmit Sensations to the Brain - Fewer Nerve Endings means Fewer Sensations
Circ. removes the most important sensory component of the foreskin - thousands of coiled fine-touch receptors called Meissner's corpuscles. Also lost are branches of the dorsal nerve, and between 10,000 and 20,000 specialized erotogenic nerve endings of several types. Together these detect subtle changes in motion and temperature, as well as fine gradations in texture.
[1. R. K. Winkelmann, "The Erogenous Zones: Their Nerve Supply and Its Significance," Proceedings of the Staff Meetings of the Mayo Clinic 34 (1959): 39-47. 2. R. K. Winkelmann, "The Cutaneous Innervation of Human Newborn Prepuce," Journal of Investigative Dermatology 26 (1956): 53-67.]

 The Frenulum
The highly erogenous V-shaped web-like tethering structure on the underside of the glans; frequently amputated along with the foreskin, or severed, either of which destroys its function and potential for pleasure.
[1. Cold, C, Taylor, J, "The Prepuce," BJU International 83, Suppl. 1, (1999): 34-44. 2. Kaplan, G.W., "Complications of Circumcision," Urologic Clinics of North America 10, 1983.]

The Frenar Ridged Band, the primary erogenous zone of the male body. Loss of this delicate belt of densely innervated, sexually responsive tissue reduces the fullness and intensity of sexual response.
[Taylor, J. R. et al., "The Prepuce: Specialized Mucosa of the Penis and Its Loss to Circumcision," British Journal of Urology 77 (1996): 291-295.]