I dunno, I think it depends what the selfies are used for.

If a lot of the people taking selfies are showing their friends back home and saying "this is where Jewish people were murdered en masse in a racist slaughter", one could argue that, in net balance, the pluses outweigh the minuses.

And even if there are more crass aspects to the selfies, well even that is generating media attention that further carries the message that it is a place where Jewish people were murdered en masse in a racist slaughter.

It seems to me that all of the above fall helpfully under the category of "never forget".