I think we should look at the intent of intentional grounding. It clearly states in the rules, that it's intended to prevent Team A from gaining an advantage from lost yardage, or from lost time, by throwing a pass that is clearly not intended for a receiver. However the spike rule is a special allowance, which is deliberately counter to those intentions, despite the fact that it's a pass that is clearly not intended for a receiver.
I simply want to get rid of the extra exception, make the rule consistent. I don't like such inconsistencies in the rules across the board, and I'm in favor of eliminating them and simplifying the game.