In the old days, a lot of guys didn't use stringers, but they did twist many limbs, especially on recurves. Many longbows seem to better withstand the step through stringing process better than most recurves. I have not found either type bow to be inherently more difficult than the other to string.
Out of long standing habit, I use a stringer on the recurves and either the push/pull or step through method when stringing my longbows. I think I voided the warranty the very first time I strung my Wesley Special by using the step through.
My arms are rather short, but I like 68" bows, and I found it difficult to use a stringer on heavy poundage longbows, thus the step through stringing method became a standard. As I got bigger and stronger, the habit remained.