Love bold statements that say nothing...
There are no SECURITY ISSUES regarding people buying or wearing guest name tags. They are a nice Disney item that was sold with a kit to make them into a luggage tag, name tag or key chain. That's all.
Do other guests occasionally mistake me for staff in the parks? Yes, but it's not a frequent occurrence and certainly would not be something someone with criminal or nefarious intent would be wearing a name tag in order to take advantage of. People who really want to do bad things can easily do so without wearing a coloured tag instead of a white tag in hope of someone asking them for help because they're mistaken to be CMs.
My personal opinion is that Disney stopped carrying them in the parks because they weren't a high-traffic item. People who bought them were usually hard-core Disney fans as opposed to casual guests. Most people familiar with "personalized" Disney items think of having their name embroidered on a set of Mickey Ears, not on a luggage tag. If items don't move relatively well in retail, you stop carrying the items.
The on-line store that does still sell them appears to have the engraving done by Disney when you order one. All the tags they sell have the following disclaimer:
By request we will have Disney engrave a name on the tag.
Disney will only engrave common proper names.
They will not engrave anything related to or resembling a Disney character name.
DISNEY HAS THE FINAL SAY ON WHAT IS OK TO ENGRAVE.
Would Disney still do the engraving on the tags if they had discontinued selling them for security reasons or didn't want guests wearing them in the parks? Not a chance. It's simply that it wasn't cost effective to continue selling them themselves.
That site doesn't appear to be affiliated with Disney in any way. Also, the above isn't a "disclaimer". All it is is a statement saying they will "request" to have Disney engrave the name. Doesn't even mean that Disney will in any way be involved.
I think it's pretty clear and obvious that Disney stopped selling them because they didn't want people to mistake non-CMs for CMs. And yes, I do agree with other posters who stated it could be a security issue. Someone posing as a CM is much more likely to be trusted by an unknowing guest. I think the potential for guest security being compromised by such an issue is very obvious.
I also think that at this point, anyone who wears one of these name tags in the park has to know that there will be guests who mistake them as being someone who works at the park. I tend to think that, regardless of what someone wants to claim as far as "not caring" what guests think, it's pretty obvious that a person wearing it in the park clearly WANTS people to think they are a CM.