I know technically it's a long occurring flavour which didn't get isolated until relatively recently, but still you'd think it'd have been known (or at least marketed) under some other term than just a plain chemical description.
It is marketed under a specific name. After Kikunae Ikeada isolated the substance he began selling it under the brand name Aji-no-moto 味の素 (Essence of taste) in 1909. You can still buy it under that name, still sold by the same company.
https://www.amazon.com/Ajinomoto-Seasoning-Monosodium-Glutamate-Naturally/dp/B00I0M99MU?th=1
It probably never got a trade name in English since unlike East Asians, Westerners never seem to use it at home. Since Western consumers are not buying it, only bulk food producers, there is no need for a trade name.
Hey there,
Just to let you know, your question is fine, and we're letting it stand. However, you should be aware that questions framed as 'Why didn't X do Y' relatively often don't get an answer that meets our standards (in our experience as moderators). There are a few reasons for this. Firstly, it often can be difficult to prove the counterfactual: historians know much more about what happened than what might have happened. Secondly, 'why didn't X do Y' questions are sometimes phrased in an ahistorical way. It's worth remembering that people in the past couldn't see into the future, and they generally didn't have all the information we now have about their situations; things that look obvious now didn't necessarily look that way at the time.
If you end up not getting a response after a day or two, consider asking a new question focusing instead on why what happened did happen (rather than why what didn't happen didn't happen) - this kind of question is more likely to get a response in our experience. Hope this helps!