为什么国外的文章中condom这个词多数是使用复数而不是单数？

for example:
Some doctors say Truvada is a step toward ending the threat from AIDS. But some critics say the drug could give people a false sense of security and make them less likely to use condoms. Critics say it could also take financial resources away from more cost-effective methods of prevention, like using condoms.

The first possibility,their condoms may be made in Japan.One condom cannot cover the dick.So they need more than one.
Sec.their dick is not big enough, can not satisfy a woman, so accustomed to using multiple.

额