So many wood bodied planes were set aside in the later part of the 19th and early part of the 20th century they probably weren't treated to a temperature/humidity controlled environment. They likely did not receive the regular care from an owner or user.
We see very few that were regularly wiped down with oil or wax.
The harsh environments where most of these planes were stored may have more to do with their cracking than anything else.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)