Я думаю, это то, что называется cultural differences.
In Russia, we don't smile at each other just to say 'it's ok' to everyone we meet. I think that 'it's ok' in Russia is when nobody is attacking you. ))) If you smile to someone in Russia you are saying that you are glad to see this person. (Usually I feel no particular happiness when seeing all these faces around me, so why should I smile?).