This is an accumulation question that comes to mind only over years of watching games.
Referees are typically generous in placement of the ball for the taking of a free kick unless it’s advanced unreasonably closer to the goal (sometimes, just sometimes an inch beyond the corner arcs) OR when the ball is advanced beyond the penalty area or beyond the halfway line. There is no instruction I’m aware of that says that placement must be within the bounds of either area. But, I keep seeing referees force the ball back before the kick is accepted. This seeming pettiness goes against the ambition of keeping the game flowing without unnecessary interruption.
Why do referees do it?
USSF answer (March 9, 2009):
To prevent players from gaining an unfair advantage.