I don't know what "willy-waving" means so I hope it's not something I'll do.
Gm4's suggestion was : - a story mode = a unchallenging mode - a RAW mode = a strict RAW mode that exclude anything that don't belongs to D&D. - an extreme RAW mode.
When reading "remove highground" you may understand "remove advantage from highground" and I may understand "remove any bonuses from highground".
Your words and quote and screenshot won't make your assumptions stronger because I have the same opinion since monthes : highground shouldn't give an Advantage.
On the other hand in a tactical TB game and even more - in a world build with A LOT of verticality - it would be stupid not to offer players mechanics to play with higher ground (or to limit them to a boring and unchallenging story mode).
I find shove OP and I'd like them to tone it down. I hate that we have an Advantage going higher and I'd like other bonuses. But as many players I like that being higher (or not) mean something.
As OcO said you already have (very) situational bonuses and that's cool but very limited.
RAW or not, a better range make sense and is an interresting bonus in tactical games. On the other hand a lot of players complain that we're missing too often and I guess that's why they implemented advantages for highground and backstab. A flat bonus is something that allow players to miss less and that can be easily custom for everyone to play with or without it.