In my opinion WT has benefited from what's known as cognitive disfluency (i.e. The harder you have to think to understand a concept or idea, the more it sticks to you).
So concepts as the times of gentiles, 2,520 years, and from there 1914, the generation, etc. take so much to understand and assimilate, they end up sticking you; by the time you 'master it' and are able to explain it to others, it becomes deeply ingrained, no matter how little sense it really makes.
At the same time, and by the same token, changing the 'Generation' understanding so many times in such a brief period becomes an attack, an undermining of a core belief of many. In other words, they spent 70+ decades instilling in us the 1914 generation teaching, and now they are taking it away. This is not sitting well with many JWs.
Add to that how stupid and arbitrary the 'overlapping generation' teaching is...