Originally Posted by
melville
What you saw has been SOP for 100+ years. Fear not.
Keep in mind that the bike weighs ~25 lbs. I presume you weigh some multiple of 25 lbs and you put all that on the seat. Have you damaged your frame by riding it? I think not.
Actually, it's more like 50+ years:
http://www.parktool.com/about/history.asp
Your comment about the stress a bike repair stand puts on a seat post versus the stress the weight of a rider puts on it is right on. Seat posts are pretty strong.