May not have been a necessity to some in the literal sense, but c'mon - a non-hard drive, single floppy system back then was a total compromise. Everyone I knew that couldn't afford an external drive at the time of purchase (including myself when I bought the A1000), that was the very first thing they saved up for. Well, that and some RAM. 
To put his words into perspective:
USA guys, please understand that in Poland where he (and I) lives/lived external floppy disk was as uncommon as floppy drive for small Atari. I owned Atari (my father saved for it over a year) from early 1990 till 1994 and I NEVER SAW ANYONE with floppy drive for it, me included. Not even in local "game clubs" where you could sit and pay for game time (that was my first computer experience, not counting reading local IT magazines). I NEVER SAW anyone with "big" atari (ST/Mega/...), which I dreamed of.
A500 was totally out of reach for like 99,9% households in the 80's, and for like 97% till 95. In highschool (93-97) I borrowed money from a bank to buy Sega Megadrive (12-months contract), and saved another month for my first cartridge from local shop, where I could swap it for another at 10% of full price -- it was the only way to afford games for me. When planning to buy Sega I calculated, that I could buy bare A500 if I was saving for 20 months. And I worked :-).
You probably can't imagine situation like this, but in Poland if you entered a "computer shop/computer club" any time till 94 (then our copyright law was stiffed), it was granted that on monitor you'll see X-COPY, laborously copying another disk for another kid for a relatively small fee. It was the only "software" other than games known to most of Amiga users :-). Couple dozens of dollars for a game was just impossible for us to afford -- in Poland you could live for that for a month :-).
To recap, I also never saw an Amiga with external floppy. And my cousine (also working student), happy Amiga 1200 owner could afford to buy his first accelerator (030/8MB) for Amiga in year 2000... PowerPCs and 060 we experienced mainly in magazine reading :-)).
That's what it looked like in developing countries from behind the "iron curtain".
