The PTV should be considered in relation to the area the tile is placed in. In many instances the PTV in wet conditions should be checked and recommended by the tiler.
I am in the process of choosing and ordering tiles for a butchers floor which is often covered in blood and needs hosing down daily. I find it safest to turn to experts like Dorset Wooliscroft (now part of Original Style family). They give PTV for both wet and dry conditions in their tile brochure - I am recommending the butcher goes for a wet PTV rating of 54, and will specify epoxy grout.
As to whether or not commercial shop traders need anti-slip tiles - well has anyone been into a Debenhams lately? Polished porcelain on the floor, but with matting at the entrance, and additional floor mats placed near the entrance when heavy rain falling outside. As tilers we can recommend and point out the risks of certain types of tile, but the use of the floor is up to the individual in charge of the premises.
So that kinda answers my feelings on the survey. As tilers we need to be informed, advise and make recommendations. I often give a percentage risk of (cracking, tile debonding, slip) of a danger or problem, but let the customer choose what to do. Use of the tiled area becomes their responsibility if we give informed advice. And I don't want to lose too much potential work by telling customers I won't tile if they ignore my advice.