1 can add significant time and complexity to your code trying to figure out what date format, for example, should be shown to various countries or regions. The easy solution would be to show one and provide options, but then which one do you show? Do you do geoip? Then what language are you going to put it in? Do you outsource translation, or hire a translator? How do you moderate user content on a multilingual site? Do you show local prices, and if so, how often is the conversion updated (if at all)?

There are serious logistical problems to tackle, not even counting getting it all running and bug-free for every use case in every language with ever data format possible. It's a huge setback, especially if you stand to gain nothing significant from being worldwide.