i think the concept is quite a strange thing. a weird compromise between faith and logic, a rejection of dogma and an embrace to superstition.
as most of the people who believe it are buddhists and a lot of them dont believe in god. its kind of a belief for people who are not really all out full on dogmatic but still some what superstitious and religious.
as a concept, i my self personally think its badly flawed. i think science has reasonably shown that humans are a biological thing and that all biological thing are perishable and probably one of the ‘least permanent’ things around.
i dont think our gift of intellect really separates us from the animals and shows we have a soul or are gods chosen people any more than a birds capability to fly shows it is gods chosen soul owning pile of proteins.
the kindest thing i can really say regarding reincarnation is this: if matter can not be destroyed, and if every atom in our body has been here since the beginning of time, and every atom in our bodies will be here in some form for all eternity, that maybe, maybe, if all these atoms have come together at this very moment to make us, then maybe, some time in the coming eternity they will come together out of chance once again.