Your 15.6" laptop is probably closer to 40cm, allowing for the edges of the screen. Your Kogan 24" 144hz monitor you bought through ozb is actually 61cm. The so called 95 you saw your workplace buy is actually 241cm, if the lack of " on the 95 made you suspicious and you read the specifications or the fine print on the box.
I understand converting for converting's sake is complication. I'm not going to start calling a Subway 6 inch a 15.24cm (although Subway themselves say they aim for a foot long length of approximately 30cm, not 12"!). But manufacturers specify their monitors in cm or mm numbers which we then convert to inches - why should we as consumers add complication and do differently? :)
honestly if they where to start advertising in cm it would confuse me even more.
im used to inches for screens now and see no need for cm.