Why did the nfl make the celebration rule?

Answer 1

The excessive celebration rules (sometimes called the anti-fun rules) started to get stricter and more enforced around the time of the 90s Cowboys. People like Deion Sanders can be thanked for that. Essentially celebrations can not mock anyone or pro-long the game. There are many rules that make little sense (a player after scoring a TD may go to one knee and point to the sky but may not drop to two knees for example).

Essentially they are sportsmanship rules.