Do Kudos have any purpose?
Solution 1:
Kudos only does two things at this time. (From what I have found online and seen for myself).
1) Tells another player you like their camp (or liked what their market box had and you've purchased it etc).
2) Fulfills goals that earn you friendship powder used in crafting. This is obtained no other way. *
*It does seem like you get a kudos based daily goal each day to allow you to earn the powder at least a little per day.