The sample quotes are all quotes from American presidents.. not really things that everyone wants/needs to translate at translation time. We should move them out of /en/optional and into /localization/en-US. This would stop them from appearing in the translations and give other cultures the opportunity to add their own more relevant sample quotes.
That, or reduce them to a very small list of samples that are very Koha specific and might be meaningful to a wider audience. Personal favourite, but inappropriate rangi: #thingsihavelearnt if there is a mad scheme a library somewhere will be doing it ... except madder