I'd just like to add, regarding "crocodiling" at meetings - it is not as restrictive as you may believe. I have been to MANY Esperanto gatherings where languages other than Esperanto were spoken. Non-speakers are made extremely welcome, in my experience. The key is to be using the right language in the right situation. At a meeting in the US, with mostly (or all Americans) the conversation will go back and forth between English and Esperanto, to make sure newbies feel included and know what's going on (yet, still get a taste of Esperanto as a living language). These are meetings that would likely be 100% in Esperanto if newbies weren't present. At multi-national events in Europe, it isn't uncommon to come across people having a sidebar conversation in a national language, something private. And it isn't uncommon, if a non-speaker or beginning speaker is present, to pause a conversation to give someone a translation of what's going on.

The rule against "crocodiling" may sound strict on paper, but Esperanto speakers are people, and it's about inclusion, not exclusion. That's why people will happily give a translation to someone who doesn't understand what's going on. Conversely, that's why the idea of crocodiling exists at all - because if you have a group of people together, and a few of them are fully capable of speaking Esperanto, but are choosing to have a conversation that no one else can participate in, it's rude. Crocodiling is not about using a language than Esperanto, in and of itself; it's about using another language, when you are capable of using Esperanto instead, in a situation where you are excluding people through your use of another language.