I had the same experience the fort time i used GC White. But the second time I use it I applied it with a DA Polisher and blue pad. Went on easy, let it dry for 20-30 minute and it wiped away pretty easy (not as easy as a sealant or their 5050 but a lot easier than before). Results were great...
The short answer...
Because I already had the Sealants on before White was available. The paint was smooth so I saw no need to reclay and just put the White Wax on top to see what it looked like.
FYI I'm still new at this and I'm playing around with different product to see what I like.
I have used Klasse HGSG and Chemical Guys JetSeal 109 on my white cars as will as Chemical Guys 5050 wax and their new White Wax on top of the sealants.