I never use the tags, they offer very little value in my mind.
For lost baggage, the vast majority of lost and reunited bags happen through the luggage tag or the barcode sticker not the BAEC bag tag.
For increased service for PAX with a GC showing, I've not observed any difference. I suspect those that have are subconsciously buying too much into the marketing.
From a risk perspective, I think showcasing a gold card increases your profile to a potential thief. A thief will not naturally think that a company has funded that gold card and would reasonably conclude it was self funded and therefore a reflection of wealth.
The very fact that most do not use their bag tags just tells me the utility of them is limited, thus concluding those who do either do it for showing status or mistakenly perceive value in them.