Russia isn't criticizing homosexuality, it has instituted a vague ban on "homosexual propaganda", which pretty much can include anything up to publicly expressing homosexuality. This is not only an attack on people's right to privacy but also a grave threat to the freedom of expression in Russia. All things considered, a boycot seems warranted.
EU's Mogherini in Tehran to talk nuclear deal, regional issues (Reuters)
from the article: Boycott the Sochi Olympics