All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The Hadeeth referred to in the question was reported on the authority of Abu Hurayrah that the Prophet said: "Verily, the most burdensome of prayers upon the hypocrites are the ‘Ishaa’ and Fajr prayers. If they knew the blessings that are in them, they would come to them even if they had to crawl. Certainly, I was about to order the prayer to be established and command a man to lead the people in prayer, then I would go with some men with firewood to the people who were absent from the prayer and I would burn their houses with fire.” [Al-Bukhari and Muslim]
The Hadeeth relates to men only because women are not obliged to perform the prayer in congregation at the Masjid. The intended meaning of the Hadeeth is that the hypocrites find it difficult to perform ‘Ishaa’ and Fajr in congregation at the Masjid. Ibn Daqeeq Al-‘Eed wrote, "The words of the Prophet ‘The most burdensome of prayers,’ refers to prayer in congregation even if it is not stated in the Hadeeth explicitly because the context indicates that meaning. The Prophet also added: ‘they would have come to them even if they had to crawl,’ and ‘the people who were absent from the prayer,’ and this indicates that the intended meaning is performing the prayer in congregation at the Masjid.”
Therefore, scholars considered such an act as a manifestation of hypocrisy in action and not hypocrisy in belief because in case of the hypocrisy in belief, the doer does not perform the prayer when he is alone at home (he only performs the prayer before people). Az-Zarqaani wrote in Sharh Al-Muwatta’, "This is hypocrisy in action and not hypocrisy in belief that takes the doer out of the fold of Islam, because the disbeliever does not perform the prayer in his house. He performs the prayer in the Masjid as a means of showing off and ostentation. Once he is alone in his house, away from people’s eyes, he celebrates his disbelief and ridicules Islam and Muslims as Allaah, The Almighty, describes him in the Quran.”
Hence, when a person feels that performing ‘Ishaa’ and Fajr prayers in the Masjid is rather difficult and burdensome, that is a sin indicative of the weakness of his faith. On the contrary, the true believer who has complete faith does not feel that burden given his strong faith in the rewards he would earn by going to the Masjid.
The same applies to the woman who feels that performing ‘Ishaa’ and Fajr prayers at home in their due times is difficult because of sleep and she performs them after their end times. This is considered a sin indicative of the weakness of her faith.
Allaah Knows best.