Hi!
One quick thought that would help both sides: don't volunteer to answer QSL cards if you know you can't get them out in a timely manner. It saves the volunteer from being rushed and constantly bothered to do something for which they're not being paid and it saves the receiver of the card the nervousness and impatience of not getting a card as soon as they can.
First of all, define "timely manner". This is a very subjective standard, and will differ based on the QSO/QSL scenario.
If someone doesn't want to deal with QSL cards, this is something that could be clearly noted on QRZ.com. In fact, that site now has yes/no questions for how QSLs are handled by stations - by mail, eQSL, or Logbook of the World. Using the biography section in your QRZ.com entry to clearly spell this out is also recommended to get the point across.
For others, real life can get in the way of this hobby and this part of the hobby. Think work, family, etc. For me, I have been at events representing AMSAT (along with other operating) over the past 5 weekends in different locations around Arizona, Nevada, and California. I have one more event coming up this Friday evening in Tucson, before I have a weekend where I can be at home for more than part of one weekend day. I am behind in my own QSLing, going back to a couple of events in mid-February in California and Arizona. All of these QSOs have been uploaded to Logbook of the World, sometimes the same day the QSOs were made, or within 24-48 hours of the QSOs. I enjoy answering the QSL requests I get in the mail. In fact, for most of my road trips, I will typically send QSL cards out to everyone I work - even if I didn't get a request from them in the first place. Especially if I had been operating from rarely-heard locations on the satellites.
Since I should be home on Saturday and Sunday next weekend, I should have time to get cards printed for all of those events and the different locations I've worked from over the past couple of months. I hope to get the majority of those QSLs to the post office by next Monday morning. Even for QSOs I made in mid-February, I would consider this to be responding in a "timely manner". You might not, and others might not, but that's the problem with a subjective standard.
It's unfortunate that NX9B resorted to sending KO4MA that e-mail. I am glad to see that Drew took the matter public, to disarm the threat from that e-mail.
73.
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK