Hello! Konbannwa.
I love going hanami very much. Because it is a rare opportunity to have a
big party "outside".
In Japan, there is a saying "花より団子-hana yori dango-"
For many people, viewing cherry blossom is not important, but having a fun with their colleagues, friends, or family members is more important.

Cherry blossoms are very special flowers for the Japanese. Since Japanese school year starts in April, cherry blossoms are always related to new life or new friends and reminds me a sweet sentimental memories of childhood.

I think hanami got its popularity in Edo period when gardening was a national obsession. After Somei yoshino (Typical type of cherry) produced by breeding
in Somei (Name of the place near Sugamo, Tokyo), then Shougun orderd to plant them everywhere. ( I'm sorry if I'm wrong.)

The time for plum blossoms and peach blossoms are still cold to have a party outside that's why they are less popular in Japan, I guess.

Maciamo-san,
I think every country has something unique (or they believe it's unique). Why not for Japan?