(Actually they're not crazy, it's a perfectly valid opinion)
Just watched a lecture by John McWorter
on the Teach Company. Particular the things he said about how languages change when people start to write them down. If he's right, then toki pona is screwed.
Once languages are written down, the sentence length goes way up and people can give their writing a hyperclarity and hypercomplexity that you can't get away with in spoke speech. So if we wanted toki pona to stay simple, we really should switch to using it in speech alone, which puts a cap on sentence length and what constructions you can put together on the fly without careful revision and editing.
On the otherhand, once written, the language evolves somewhat slower. The toki pona essayist can look up all attempts to translate ostrich, nail polish, which have historical precidents, but aren't words I would have guess without reading them first. An oral toki pona would rapidly forget words, errors would become permenant faster. Also, people tend to be in the toki pona community for about 2 years tops, sometimes five. When people are entering and exiting a language community so fast, it recreates the conditions of generations in natural languages, but sped up by a factor of ~40. If it weren't for writing, toki pona should be evolving as fast as natural languages do in 400 years.
So, if we write, toki pona will become complex beyond a typical pidgen. If we only talk on skype, toki pona will become an entirely different language within our lifetime.
Chat is an unkown quantity, it's real time but written. What chat-room-ism have you seen evolve, is it more speech like or writing like? And off the top of your head, without looking up, what would you call ostrich, nail polish and armadillo?