The Meaning of the Word "Windbag" in the usual context of internet conversation is grossly misunderstood by many well intentioned contributors. For example: "On this day in history" followed by several pages of cut and paste. It simply means they have nothing better to do with their time. Whether there's an emotional involvement or not is never the issue they just love pretentious gassing.
According to American Heritage® Dictionary of the English Language,
(Fifth Edition. Copyright © 2011 by Houghton Mifflin Harcourt
Publishing Company. Published by Houghton Mifflin Harcourt
Publishing Company. All rights reserved.)
1. The flexible air-filled chamber of a bagpipe or similar instrument.
2. Slang A talkative person who communicates nothing of substance or interest.
According to Collins English Dictionary –
Complete and Unabridged
© HarperCollins Publishers 1991, 1994, 1998, 2000, 2003
1. a voluble person who has little of interest to communicate
2. (Instruments) the bag in a set of bagpipes, which provides a continuous flow of air to the pipes
According to Random House Kernerman Webster's College Dictionary,
© 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by
Random House, Inc. All rights reserved.
an empty, voluble, pretentious talker.
Little Boy Blue,
Come blow your horn,
The sheep's in the meadow,
The cow's in the corn;
Where is that boy
Who looks after the sheep?
Under the haystack
Will you wake him?
Oh no, not I,
For if I do
He will surely cry.
Tommy Thumb's Little Song Book page 666