I don't believe that stream entry is a secular term. It is strictly used in Buddhism and is based on thing's that lacks evidence in terms of existing (such as past lives and future lives).

It is most important because according to Buddhism, the person that attain's stream entry is seven rebirth's or less from attaining awakening at which point they will not be born again.

If we look at stream entry from a secular point of view it does not make much sense to attain it since the benefit's that come from it are really only important from a religious context (only 7 rebirth's or less until enlightenment, no more lower rebirth's, having a bad mindstate at death does not lead to lower rebirth's anymore because stream entry manipulates the way that karma effect's the individual, and son and so forth).

So as you can see, the benefit's are mostly religious in context and deal with karma, rebirth's, and Buddhist awakening (awakening differs from religion to religion).

While it is also listed that a stream enterer will also never kill their mother or father again, one would have to be insane to do something like that in the first place although it was possibly more common back in ancient India especially in regard's to untreated mental illnesses which were probably really rampant back in the Buddha's time.