To those who criticize ex-Muslims for hiding their identity, we'd like to point out that even the Prophet Muhammad himself initially kept his prophethood hidden for three years. Additionally, many of his companions hid their beliefs to avoid harm, as encouraged by Quran 3:28. 

Quran 3:28:

(Let) not take the believers, the disbelievers (as) allies from instead of the believers. And whoever does that, then not he (has) from Allah in anything except that you fear from them, (as) a precaution.

Ex-Muslims face significant danger and persecution from radical Muslims, far surpassing what the early Muslims faced from pagans. While it's true that pagans restricted the preaching of Islam and conversion, it's important to recognize that Islam and its radical followers sometimes perpetuate similar restrictions and even worse treatment of those who leave the faith.

If pagans put restrictions upon preaching Islam and conversion of religion, then they acted wrongfully. But unfortunately, Islam and its radical followers are themselves following the Sunnah (practice) of those pagans, whom they condemned for that crime. Actually, their behaviour is even worse than the pagans in this regard and they kill ex-Muslims immediately for leaving Islam. 

Ibrahim declared her wife Sarah to be his sister and also sent her to the King

Prophet Ibrahim (Abraham) told lies three times, including when he referred to his wife Sarah as his sister to protect her from the king's intentions. 

Sahih Muslim, 2371

Prophet Ibrahim never told a lie but only thrice: ... He had come in a land inhabited by haughty and cruel men along with Sara. She was very good-looking amongst the people, so he said to her: If these people were to know that you are my wife they would snatch you away from me, so if they ask you tell them that you are my sister ... so he (the king) sent someone and she was brought to him, and (instead of fighting against the kidnapping of Sarah) Ibrahim stood in prayer ... (and the tradition further tells after this cowardice of Ibrahim, Allah had to defend Sarah himself from being raped by the King).

In brief, Ex-Muslims have all the right to hide their identity to save themselves from the HARM of Islam and radical Muslims. And these radical Muslims should be ashamed of their evil intentions of killing innocent ex-Muslims, and they should reform themselves instead of blaming ex-Muslims for cowardice.