Sorry not everything posted, trying again.
Your link site starts off with a wrong assumption. That is what the WTB&TS does, plants a thought and than builds it to their own liking.
The skeptic?s bible says, God likes Abel's dead animals better than Cain's fruits and vegetables. Why? Well, no reason is given, but it probably has something to do with the amount of pain, blood, and gore involved. 4:3-5
NIV Genesis 4:3-7
3 In the course of time Cain brought some of the fruits of the soil as an offering to the LORD . 4 But Abel brought fat portions from some of the firstborn of his flock. The LORD looked with favor on Abel and his offering, 5 but on Cain and his offering he did not look with favor. So Cain was very angry, and his face was downcast.
6 Then the LORD said to Cain, "Why are you angry? Why is your face downcast? 7 If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must master it."
Cain brought some of the fruits where Abel brought fat portions and the firstborn. Abel gave of his best, where Cain did what he had to. It was not what was given, but how it was given.
In verse 7 God could see that Cain?s heart was intent on sin and it was close by.