Well, for me it was opportunity. When I started looking for my first bike, a project bike, I looked at a number of early 80's bikes that just didn't catch my eye. Closer to cruisers - high bars, more rake in the front end, tank sloping up from the seat etc.
I found a 1977 CB750K that fit the bill. That got me onto the original SOHC4 members site (greenspun). I learned so much about the general SOHC4 family line, that my next bike (1973 CB500K) and then my current 1976 CB550F were natural choices.
If I had $4000 to spend all at once on a bike I'd probably look for a mid-70's BMW R75/5 or the like. But, I love the styling of my Sunrise Orange CB550F and love the size. I'm into the bike for a grand total of CAD$2,100 including a full top end rebuild (new pistons, bore, valve job, carb rebuild, points, condensors, etc. etc.). I now know what's inside the bike and that gives me a good sense of comfort. Kind of like my 90 year old house. I'm not happy until I've ripped it apart and rebuilt it so I know what's inside the walls.
So, long story short, and it's a great credit to the community on this board - it's the SOHC4 Forum that kept me in the family.