Until airsoft grenades can be made to effectively mirror the weapon system they are based upon I can understand and respect the restrictions on their use.
And if you think by drudging up old posts by us long term members to prove (or think you do) that we at one time felt as you did you are not helping your point nor making friends in this community.
I have seen many times altercations break out at games because of discrepancies between expected and actual outcomes of the use of mock weaponry. Whether it be shooting through brush, throwing a grenade on the other side of a tree, expected range of airsoft guns, expected range of area effect weapons, people using the fake weapon expect to get an outcome and are often disappointed when that outcome does not happen, even if it is through no fault of their own, or the device. Limiting grenade use is the prerogative of the organizer and though you define a "milsim" game as one that must involves grenades, they may define it otherwise.