Secular Buddhism is just nihilism
Secular Buddhists are generally comfortable with the term "agnostic", a term coined by Thomas Huxley (18251895). The agnostic takes pride in know nothingness, or the same, that we cannot know. Agnosticism, in this respect, is just another word for skepticism which, itself, is still another word for nihilism.
Judging from what I have seen of so-called secular Buddhism, philosophically speaking, it is veiled nihilisma happy or spiritual nihilism you might even say. There is no rebirth or reincarnation. This is our last life and when we're dead, were quite dead.
Describing my deeper sense of this benighted phenomenon, I have to look back to Nietzsche who prophesied the coming of nihilism for the West. He turned out to be right as prophets go, seeing nihilism's dark clouds encircling the globe, blocking out the sun of spirit and wisdom to such an extent that it is acceptable to deny the very spirit that animates us.
When a secular Buddhist writer equates Buddhism with agnosticism as Stephen Batchelor does, rest assured that he is not far from Nietzsches prophesy. What the modern Buddhist is taught, essentially, is the Buddha is the common man; his Dharma is sensory perception; and the Sangha is the natural world. When he dies, this is the attainment of nirvana.