Even if thats the case then that is the advantage of covers and walls, how aften an ally dies in the spot where mercy can glide and take cover? If i see a dead ally in an open i wont rez it unless its safe but if the opportunity of wall and cover arrived then its an advantage.
If a dva bomb is launched and cover is present people would hide behind it its the same concept. Mercy is just gliding slowly compare to the rest but somehow its unfair? lol and the OP didnt account the range of 5 meters,
i had tried to rez and fall many times in a place where my team dies at the top of a building and once i fell far enough my rez got cancelled. Its a hit or miss depending on the range