I don't think so.
I have been to the memorial, inside the school for a holiday fair (there is a homemade soap stand that is perfect for Colorado winter and it is the only place it is sold!) and lived in Littleton for work, there are many parks, hiking trails and outdoorsy things to do. When I was at the memorial for the anniversary I got hugs and smiles. Nobody bats an eye. I know strangers leave flowers at the victims graves on the anniversary and I have never heard of anyone having a bad experience.
The only time I imagine that locals get annoyed/angry is when people act like a fool and try to get into the school or slowly try to go by E and D's house
This one girl on Tumblr who is VERY obsessed with Corey D was at Clement Park for the anniversary and wrote something on the sidewalk up to the hill. I didn't see her but it was very obvious it was her, about how they are soulmates and how she will always love him..and then signed her name, which is the name she goes by online.
Littleton does not have anything that is touristy, it is really residential.
I think Draw It White may have had a different experience/vibe when he was there but I don't want to speak for him.
"And you know, you know, you know, this can be beautiful, you say you're numb inside, but I can't agree. So the world's unfair, keep it locked out there. In here it's beautiful."