i completely agree; even the one's that do get round to demoing them often spend the majority of the video taking it out of the box, talking about how shiny and awesome it is, and then record 20 seconds of shoddy vocals. The last time i was on a new mic hunt i had a ganders round youtube for clips and there was a ridiculous amount of "unboxing" videos.
To me, posting unboxing mic videos is like someone posting "unwrapping your christmas presents for you" videos; part of the joy of getting new gear is getting it out of the box and videos like this take away all the surprise. granted, i can understand people wanting to know if it comes with a shock mount/wind shield/other extra's but 9 out of 10 times these details are in the manufactures specs on stores websites