People question us why was Jamaat ul Muslimeen revived? As the hadith narrated by Hudhaifa (May Allah be pleased with him) tells us to stick to Jamaat-ul-Muslimeen and in its absences to be aloof from all sects even if we have to chew the roots of trees till our death.
In response to this we point out that the hadith narrated by Hudhaifa (May Allah be pleased with him) tells us if we are forced by people to chew roots of trees, then do it, but don’t join any sect. It doesn’t tell us to go to the jungle and die, but only describes the worst situation that might arise.

We do not seek the teachings of Islam in one particular ayah or hadith but in the entire Quran and Sunnah, we have to observe many ayaat and ahadith to reach a conclusion. In the mid 1960’s when a handful of people decided to depart from all sects in the light of the above mentioned hadith, they also had to follow the following ayaat and ahadith.

Together hold Allah’s rope firmly and do not become sects.
(Surah Aale Imran, Ayah 103)

In this ayah Allah has commanded the Muslimeen to remain united and forbade them from breaking their unity, meaning not to secluded from other Muslimeen but remain united and live in the form of one Jamaah. That was what those people did after leaving all sects.

Who could be better in words than the one who invites towards Allah, performs righteous deeds and says surely I am among the Muslimeen.
(Surah Ha Meem Sajda (41): Ayah 33)

They are to declare themselves to be Muslimeen, which is what they did and they gave up all sectarian names.

Prophet Muhammad (SallAllah-u-Alaihi-wa-Sallam) said: It is not halaal for three men that they live in a jungle but make an Emir from amongst them. (meaning to live in a jungle without an Emir is forbidden).
(Narrated Ahmad and Sanad is Sahih. Buloogh ul Amani Vol: 19, Pg. 288, Ijtimaiyaat aur Islam pg. 2)

Prophet Muhammad (SallAllah-u-Alaihi-wa-Sallam) said: When three people leave for travelling they should appoint an Emir amongst themselves.
(Abu Dawood: Kitab ul Jihad, Sanad is Sahih and declared Hasan by Albani. At-Taleeqat-alal-Mishkaat 2/1145, Minhaj ul Muslimeen pg. 527)

Whether in the jungle or in travel we are forbidden to live without an Emir, so how is it possible that we can live our normal lives without an Emir? Syed Masood Ahmad was nominated to be the Emir of those people who had departed from all sects.

Prophet Muhammad (SallAllah-u-Alaihi-wa-Sallam) said: Upon you Jamaah is obligatory, escape from being separated as Satan is with one and distances himself from two.
(Tirmidhi Vol. 4 pg. 404, Imam Tirmidhi said this hadith is Hasan Sahih, Firqu mei Jamaat ki pehchaan pg. 7)

We are ordered to remain united and in the form of one Jamaah, this unity of Muslimeen in the form of a Jamaah has been called ‘Jamaat-ul-Muslimeen’ by our Prophet (SallAllah-u-Alaihi-wa-Sallam), so Masood Ahmad and his friends became Jamaat-ul-Muslimeen by following Quran and Sunnah, and in practice of sunnah they named their Jamaah ‘Jamaat-ul-Muslimeen’. Jamaat-ul-Muslimeen was a forgotten Sunnah, which was revived by Masood Ahmad and his friends.

In the end we can conclude that for an individual it is not allowed to join any sect in the absence of Jamaat-ul-Muslimeen even if he has to leave all his friends, family, live in the jungle and die while chewing the roots of trees. But if he is joined by other Muslimeen, then they all are to live in the form of a Jamaah, appoint an Emir upon themselves and call themselves Muslimeen, their Jamaah will be referred to as ‘Jamaat-ul-Muslimeen’ as there is no room in Islam for any Jamaah or sect other than Jamaat-ul-Muslimeen.