Because different words have very different best potential performance characteristics when used as wake words.

We would have liked to enable fully custom wake words, but it would have led to bad user experiences with the device either failing to wake up too often (false negatives) or having too many false positives or both.

So we compromised by enabling more than one, but not full choice.

I just wanted to let you know that you have caused great distress to my aunt, my daughter and my wider family through you and your colleagues thoughtless actions.

I hope someday you, and Amazon as a whole, gets its comeuppance.

I'm sorry if that's the case, but our actions (at least with respect to "naming" Alexa) were extremely far from "thoughtless." There were literally thousands of hours of research, analysis, engineering, and "thought" involved.

Please don't personally attack people.

Thanks for the insight.

Is it difficult to fingerprint a sound bite? Have people repeat it several times and again for each user that wants to use the custom wake word?

It's not so much the "fingerprinting" - it's more that there are some words ("type 1") that have many relatively frequent words that sound like them, and there are other words ("type 2") that only have a very few other words (and infrequent ones at that) that sound like them.

Type 2 words make better potential wake words.

(That's not the whole story, but I think it's good model.)

from my observations of the masses that Alexa and co try to cater to, that's too much work or too technical. we have to remember the average joe/jane don't know what a browser is.