Ok of course you can reply, I was in no way excluding you

I'm not confused at all, I realise that certain labeling is a legal requirement, whilst others are purely informative ... stating that meat sold was 'halal' would be in the later, informative.
We live in an age where many people are concerned about what they eat, (I know equally many aren't and if it fits in their mouth they will eat it), some want to know if it's 'organic', others if it's 'free range', still others want to know about animal welfare if it is an animal product, or some other provenance.
For some people halal slaughter would be unacceptable for their perceived view of the animals welfare, for others it would be unacceptable as it has been killed in a form of religious ritual that they would find objectionable.
For most people, they think that they are aware of the 'normal' process of slaughter and the halal process is not what they consider to be the normal way, hence 'different' ... they may or may not have concerns about that.
Just because you or I have no concerns, does not IMO, affect the fact that such a process should be clearly indicated in order for those who do find the process unacceptable to make an informed choice.
For me, it all comes down to, not whether it's a Muslim, Jewish or whatever thing, it's a case of being able to make an informed choice over what you eat and having a clear understanding of the provenance of that product.