Asgorath
Explorer
Where you and I differ is that I have no aversion to ambiguous rules. When a rule is ambiguous in its meaning, I simply decide based on the context what it should mean, and play accordingly. You, apparently, need to parse out the exact semantics of the terminology and take that as the meaning of the rule, no matter how ridiculous that meaning might be (case in point, disintegrate a perfectly healthy druid.) It often appears to me, as I view or participate in these conversations, that if a rule can be read in more than one way, you will pick the worst possible interpretation and then argue vigorously that it is the only correct way to read the rule. If Jeremy agrees with you, so much the better.
Disintegrate vs wild shape was an ambiguous rule, as demonstrated by hundreds or thousands of posts disputing the "correct" interpretation of the rule. Clearly, the "correct" interpretation of Shield Master's bonus action is also ambiguous. It will be interesting to see whether or not Jeremy amends it with errata, and if he does so, how. I'm tempted toward the suspicion that he will leave it ambiguous, just so that people can continue to interpret it how they feel is appropriate, but that's probably me projecting my own peevishness onto him. He probably regards ambiguity as his own personal kryptonite.
A lot of the arguments in the past thousand posts have read as "I really want to shove first, so let me warp the meaning of the words to support my position". The PHB doesn't talk about the duration of an action. The PHB doesn't talk about the Attack action being separate from the attacks themselves. The PHB doesn't talk about just doing stuff and resolving what was an action and what was a bonus action when your turn is over. The PHB does use standard phrasing across multiple rules, and tends to be very economical in its use of the language.
As I've said many times, I can absolutely agree that attack-shove-attack is a reasonable interpretation of the wording of the feat, because once you've taken the first attack you have committed yourself to the Attack action. My only real issue with that is that there is a condition on the Shield Master bonus action, and so we can go off into the weeds whether "take" means "taken" or "taking". However, we haven't been debating that for the last couple of hundred posts, unless I'm missing something. I'm simply advocating for taking the simple approach and not reading things that aren't in the words in the PHB. If the PHB doesn't talk about action duration, then action duration isn't a thing. If the PHB doesn't talk about the Attack action being separate from the attacks themselves, then that's not a thing. Just do what it says on the tin.