I agree, although some members might not have merits to give.

Just writing "Thanks" or a short phrase to express gratitude is pretty much the same thing as "nice project" or "joined" or any of those types of posts which are banned in the altcoin section.  But I'm not sure a thank you should automatically be deleted or even reported, because it's not quite as spammy as those other phrases I listed above. 

In any case, OP, if you want to thank someone in a post (and I hate to even suggest this), perhaps try padding the post a little bit with more content.  At least then it's not likely to get reported and deleted.  And yes, moderation here is strict as far as low-value posts go.