I guess people slide that in, because if it's not included, people often start to ask "why not destroy it?". I have been guilty of this myself…people don't want to have to flip the status on their item to "neutralized". So, to keep them safe, they are made Indestructible.
I can understand the argument for and against this trait. It's understandable that these objects may be:
A: made of materials so strong nothing we have can harm them
B: composed of stuff so outside our reality that, while it may be made of something soft and pliant, it is too far from our physical laws to be damaged by available means
C: Does not fully exist in our reality to be destroyed.
However, there are ways besides indestructibility to keep an item around:
1: Item is very useful, or has potential strategic benefit
2: While dangerous, has habits or abilities that would be extremely useful if understood and used in a controlled setting.
3: The possible repercussions of the item's destruction are not yet fully understood.
4: Item is still under study, or has scientific merit
I'm currently having this issue with SCP-682…when i first wrote it, i felt it was my weakest entry, and almost deleted it outright. Then, after someone edited it, it became one of my most well-known. Now, people have decided they want the old boy neutralized. I'll probably do so in such a way as to leave it's death open-ended, but it's still hard to say goodbye.
In the end, we're all writers. It's hard to edit something you pored time, creativity, and love into, and harder still to edit and add it's destruction. Yes, the article itself is still up, but that "Neutralized" status can be a bitter pill to take.