Per day being a key part of that. 30g at once is going to give a good chunk of people pretty severe cramping or a trip to the bathroom.
I think a lot of the anecdata on creatine is probably from people misplacing confounding issues to the creatine use. People in this thread are talking about heart palpitations or trouble sleeping. Stressful days at work are enough to trigger that.
When I first started taking creatine in the late 90s (it had already been heavily studied then as one of the only supplements that improved athletic performance), I would mix it with juice. There were some studies that sugar would help the uptake.