Can the hadith "then abandon all those sects, even if you have to bite onto the root of a tree" be used to infer the obligation of shunning contemporary Islamic groups such as the Islamic Movement, the Tablighi Jamaat, Sufism, and Salafism?

It is obligatory to adhere to the جماعت (community) and abandon division. The term جماعت has two meanings: the first is the truth, methodology, and creed that the Prophet (peace be upon him) and his companions followed; the second is the community of Muslims that has a legitimate Imam. Isolation (اعتزال) occurs when both of these are absent. If there is no Imam for the Muslims, but there are gatherings that adhere to the methodology of the Ahl al-Sunnah (definition) wa al-Jama'ah, then it is obligatory for a Muslim to adhere to the methodology of the Ahl al-Sunnah wa al-Jama'ah and cooperate with these gatherings. However, if there is no community adhering to the truth, nor an Imam, but rather sects of people of desires and innovations, then the Muslim must isolate himself from these sects and adhere to the truth privately. It is obligatory to isolate oneself from sects that contradict the Ahl al-Sunnah wa al-Jama'ah, such as the deviant Sufis, whether or not there is a Muslim community and their Imam. Cooperation with gatherings of Ahl al-Sunnah wa al-Jama'ah does not imply blameworthy partisanship or fanaticism.