Because I see a lot of processes there, and the \"time\" column shows big values for all of them.
I recently needed to do this and I came up with this
-- GROUP_CONCAT turns all the rows into 1
-- @q:= stores all the kill commands to a variable
select @q:=GROUP_CONCAT(CONCAT('KILL ',ID) SEPARATOR ';')
FROM information_schema.processlist
-- If you don't need it, you can remove the WHERE command altogether
WHERE user = 'user';
-- Creates statement and execute it
PREPARE stmt FROM @q;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
That way, you don't need to store to file and run all queries with a single command.