Since when was WET a thing?

I grew up with GMT (Greenwich Mean Time, still the legal term in the UK) which was replaced for technical considerations by UTC (co-ordinated universal time) because the former isn't defined specifically enough in scientific terms.  UTC has become more obvious with the rise of the computer age because time servers use it to synchronise times between different computer systems.

WET is apparently "Western European Time," comprising the UK, Ireland, Portugal and a few other places - in other words, GMT, or UTC+0 in technical terms.  Presumably use of WET within the UK is at least in part political, wishing to identify a pro-European mindset (with a direct comparison to how different time zones are used in the US, for example).  In an international sense, using WET can only identify a pro-European mindset, as it makes more sense to use UTC+(hour) as a) it's already in common international usage, b) it ignores daylight saving fluctuations - not all WET area members will be on WET at the same time - and therefore c) it's obvious to anyone looking at UTC+(hour) what local time it actually represents, which is really the whole point.

The big downside to using neologistic terms like WET, CET, EET etc. is the same as the use of the US equivalents - if you're not American, do you know how many hours UTC differs from, say, Mountain Time?  Do you even know which areas of the US run on Mountain Time?  Tell me an area uses UTC-7 however, and I know exactly what time it is there, irrespective of the time of year.