I suppose it's nostalgia that keeps me keen on typewriters. At 62, a retired newspaper reporter and editor, my career spanned the revolution in printing technology. My first job in 1974 was at a hot-lead paper that still had Linotype machines in the basement where the massive presses shook the entire building during press runs. 
My second job was with a cold-type paper and we used Selectrics to produce copy fed into and read by a oven-size Optical Character Recognition machine that produced punched tape that was fed into refrigerator-size Compugraphic typesetters. The photosensitive paper from the Comugraphics was trimmed and pasted up with hot wax for camera-ready copy. Then in the 1980s Apples came into the newspaper business, and a lot of jobs disappeared. I remember laying out broadsheet newspaper pages on a tiny Mac Classic screen in PageMaker.
Today I have the same model Smith Carona portable I learned to type on at home in the late-1950s, a 1920s Underwood No. 5 with a ledger-sized carriage and a Selectric II, all of which I use, plus a Royal portable and a Brother daisy-wheel that are stashed away.
I use the Selectric mostly, for forms, envelopes and the occasional letter to a friend (or a strongly worded letter of complaint).
I'm typing this on an iMac, which has a poor excuse for a keyboard, but it does point out my mistakes for me.
But when I'm on a typewriter I actually enjoy being forced to think before I press the keys.

So much to say, so little space...

Why did I first buy a typewriter recently? I can't explain that. The idea was just percolating through my unconscious that I wanted one, I suppose, and sometimes breaking into consciousness. And eBay.

What got me hooked? It may seem presumptuous to say I'm "hooked" less than two months after buying my first typewriter in... a long time... but some drugs have that property. I think they just brought together a number of things for me: (1) love of mechanism (2) the similarity of the technique on a manual typewriter to an acoustic instrument. (3) that great feeling when a machine exact condition unknown either works perfectly out of the box, or you are able to restore function with a few simple tweaks.

OK, the heck with the two-tone stuff. But on the theme of "instrument", I note that a typewriter is a writing instrument and a musical instrument is ... exactly that. And both are instruments. I have no doubt brain scans of a person improvising on a piano and creating prose on a typewriter would show many of the same centers activated. Does anybody argue that the acoustic piano or the trumpet are obsolete because we can reproduce their sounds electronically? People still pay to hear other skilled people use them, and not as half-dead period instruments but living means of creation. I don't see why a fine manual typewriter is necessarily any more or less obsolete than a Steinway. And a damned sight cheaper. I have run out of space to welcome machines into my home way ahead of running out of money, even on a modest income. Guess I shall have to aspire to a house! A city boy, I never had a reason to want one of those things before. And darned if I don't love the large ones.
 

Why?  Over the past thirty-five years of typewriter collecting, repairing, and restoring, I have acquired several schools of thought.  My mother almost always had a typewriter she used to write letters and recipes.   After having taken said typewriters apart on her desk at the tender age of 12, I decided it was time to learn how to fix the things.  The first one I successfully fixed was a 1948 Remington KMC.  It took a month, but I did it.  It was nearly rusted solid, and nothing moved unless it was pryed loose with a screwdriver.  When I finished, had it painted and a new ribbon put in, I was typing away, writing homework assignments and letters alike.  Then I bought other typewriters, fixed them, and did the same.  Then I got into selling them to friends and teachers.  I even rented out a couple when I was 15.  I repaired other people's machines soon after, so instead of teachers asking me for my hall pass, they handed me money!!  So this school of thought was that it was a small business that kept me out of a lot of trouble.  I've bought typewriters by the palletful when offices were dumping them in favor of computers, paying about $5.00 for each.  I would find some beauties--some of which I still own.  This school of thought has it that it was a hobby where I enjoyed seeing something in a typewriter or group of typewriters I hadn't seen before, and I was making discoveries and learning the many different ways a machine designed to pile letters and numbers on a page could be constructed.  And then the school of thought of preservation, carrying a torch for those old repairmen whom I had known many years, and those who used typewriters, and the admiration of the repairmen, the typists, and their machines.  This is the school of thought that now means the most to me.  I do this now because I can become a voice for those who are no longer around to speak of their experiences, and their lives and times.  I even have the remnants of a front sign of one of the typewriter shops I used to visit hanging on my bedroom wall.  I keep it there in memory of a very good typewriter repairman friend of mine.