Go to samsung.com and compare tablets. The S7 has wifi. The S6 has N/A. The S6 has a battery. The S7 has N/A. The S7 has a display. The S6 has N/A.
If I'm comparison shopping, I don't want to choose between a tablet with a screen or a tablet with a battery. I'm going to pick a manufacturer that at least manages to include both specs on their web site.