Tbh I think YOU are missing the context. I hate arguing with strangers on the internet, as we both clearly have more important things to do than be annoyed with someone we’ve never met and are never likely to meet but, since we’re here….
Firstly, the OP, who flounced after her horrible, nasty comment that showed her true colours (and it’s since been deleted, but for those who wondered, she insinuated that someone who disagreed with her on glottal stops was actually on benefits, so that’s… nice) was clear that the le-uh word was not being taught/coded/instructed in phonics.
Secondly, your argument is that the glottal stop is poor enunciation. I’m arguing that it’s not. It’s part of regional dialect. (And to be clear, I don’t use glottal stops and don’t actually love the sound of them, so I have no skin in that game).
The reason I’m being so vociferous is that I do have a non-RP accent: I’m Northern Irish living in England and have experienced consistent and quite nasty accent bias. The idea that there is a ‘correct’ accent has consistently been debunked by researchers and linguists, and yet it persists. And as you can see from the Sutton Trust report, the effects on social mobility of this type of bias are debilitating and quite sad.
Your argument above that rhotic accents are fine but glottal stops are poor enunciation, not accent, have been debunked above.