Non certified types (DH Comet air racer) may not have demonstrated the characteristics which assure "not hard to land", and their vintage would suggest that norms of aircraft handling were not well established at the time they were designed. I have flown some very old types, which were obviously built to different norms (Tiger Moth), though they still flew nicely, once I learned.
I thought that my Teal amphibian taildragger (certified) was "hard to land" - but it was me, I had not learned how to handle it properly. I was intimidated by crosswinds in it, but it was me. One day, I decided to teach myself, and overcome my intimidation. I took it out on a frozen lake, in a 20 knot wind. I landed progressively more and more out of the wind, until finally, I was completely crosswind. I had no problem with it. Any previous problem I had had, was me, not the 'plane. Though, once I slowed below about 10MPH, it would weathercock, as the rudder was no longer effective, and the tailwheel slid on the ice. That was the point when I came to learn that the tailwheel really is not doing much to steer the 'plane on the runway at speed anyway, it's all the rudder.