As-salaamu caleykum,
It is true that the prophet (SAW) said, "The covenant which [differentiates] between us and them [the disbelievers/hypocrites] is salah, so whoever abandons it has committed kufr," and this hadith is authentic and has many other authentic narrations (i.e. carrying the same message). The agreement amongst the scholars of ahlussunnah is that the one who DOES NOT SEE Salaah as waajib/fardh (compulsory duty upon a Muslim) and OPENLY rejects is indeed a kaafir.
The problem I see, however, is that you're all ignoring what brother Aristote is trying to say. Sister Lexy, no offense, but you're totally overlooking the brother's message, and you seem to have a narrow, one-way view of Islam, taking the opinions of YOUR scholars to be the ONLY valid opinions in Islamic fiqh. I will attempt to show you all (hoping that you'll have an open mind) how the scholars differentiated on this matter. The question is: is the one who leaves salaah--intentionally or unintentionally--a kaafir? There are a great many scholars who have commented on this matter, but we'll only look at the four imaams of ahlussunnah.
View of Imaam Ahmad: the one who doesn't pray (whether or not he recognizes it as a duty to perform salaah) is considered a murtad. In other words, he has committed full-fledged kufr. He should be killed just like others who have committed kufr (i.e. left Islam) and his body won't be washed, no janaazah is to be offered on his body, and he shall not be buried amongst the Muslims.
View of Imaam Shaafic (who is followed by the majority of the Somalis): the one who doesn't pray out of laziness persistently is NOT a murtad (he is no kaafir), but the punishment is death.
View of Imaam Maalik: same as his student, Imaam Shaafic.
View of Imaam Abuu Xaniifah (or, if you wish, the view of his two main students, namely Muhammad and Abuu Yuusuf): the one who peristently neglects Salaah out of laziness is to be incarcerated and beaten until he begins to perform Salaah again.
This is common knowledge brothers and sisters, so instead of reply with your own opinions and just accusing brother Aristote or any other brother/sister for bring neutrality (within Islam, of course) into a heated debate, please consult a scholar.