How about something really useful such as a knock it down and make a small park , sitting area. Put the logo on the ground in bricks or tile with a marker. Simple, classy, tasteful, respectful.! Have to be sure that it really ends up as a memorial to the "victims" and not as one to the Muslim murderer/terrorist. No way to be sure that any flowers, candles, etc. are there in memory of who is considered a "victim".
It is important to remember people that we have lost. The Orlando shooting was devastating and those people should be remembered. I think that every mass shooting should put up some kind of memorial to remember the people that passed. When we lose a person that is in our life, it is sad and they should be remembered.
Mass shootings happen much too often in America and I believe that this is, in part, due to our country's short term memory in reference to these atrocities. People memorialize the victims for a number of days or weeks but if they were not affected directly, they quickly move on and act shocked when the next shooting happens. Hopefully, creating memorials from these sites would cause people to not only remember the victims, but work to ensure that mass shootings such as these can't happen again.
Why do you think there are so many shooters? Because the media treats them like anti-heroes, they talk about everything they did, how many they killed what weapon they used and now they will even have a memorial built specifically for the killer, sure that's not the intended purpose but that's what it looks like to the murderer
If we turn all mass shootings into memorials, the memorials will start to lose their meaning. In fact, most memorials have already lost their meaning as people are fascinated by them and do not give them the reverence and respect that they deserve. Memorials are tourist attractions and not sacred spaces.