The problem with using geographic names is that they are often not unique which can lead to confusion. If I tell someone that I’ve fallen and hurt myself about a kilometer north of San Vincente then if I’m in the Phillipenes the person has to work out which of teh 40+ San Vincentes I’m referring to….
Also people frequently have different names for some geographical locations, particularly locals. I once stayed in a village that had an official name that was on signposts and maps but which had a completely different name 100 years before and the vast majority of locals all still referred to it by the original name, and to make matters worse they mostly used a shortened version of the original name that was fairly un-unique.
Furthermore if I’m wandering about in a massive open extent of forest I might only be able to tell someone the name of the forest and there may be no local geographic name for the bit of it I’m standing in, the nearest identifiable named location could be a kilometer away, not very precise.
The problem with WTW is not that it is a bad idea, it’s actually a very good idea that is likely to work well in many circumstances, but more that the system is not open, or linguistically universal and therefore shouldn’t be considered some sort of global standard. It has its flaws but so do most other forms of location id, whether that be accuracy, vulnerability to change, ease of use, interoperability, universality, risk of mis-reading or miscommunication or a requirement to have access to certain equipment (such as an electronic device) or lack of an open standard. Yes it does concern me that increasing use of it may put a lot of reliance on the whims of a commercial company, but GPS itself is available at the whim of the US government or a military jamming aicraft so in some situations you may have problems trying to rely on it, whether it is through WTW or just for log/lat or a local grid ref. Maps are great but they require an an ability to read them and accurately report a coordinate system (which a surprising number of people can’t), plus if you have no location device and you can’t identify any map features then they ain’t much use. No system is perfect in all situations, WTW is just another method that can be used and for many people it will be the easiest, most accurate and least likely to be messed up.