No it is not true at all that RTwP "wreck" D&D rules. Core rules were not changed for combat in the original BG games. In that RTwP system you still had rounds and turns and weapon speed and casting time. All that happened was that time was running continuously unless and until you, the player, decided to stop it rather than the game forcing it to stop for you. Also, rather than assigning orders strictly sequentially to your characters, you can give out orders all at once and then watch as those orders got resolved over time.
P:K also follows this same system and is very much true to Pathfinder rules. It is EVERYTHING like Pathfinder.
This argument that if the pnp version of a game is TB then the computer version of the game should also be TB is a completely fake and ridiculous argument that has no logic to it whatsoever. Personally I think it is a way for people who want every damn RPG to be TB to make such a demand without also appearing to be selfish.
You're objectively wrong when it comes to Pathfinder. Its half-assed aborted implementation of flanking, for example, is a direct result of the Real Time with Pause system.
As P:K also demonstrates, action types in a Real-Time with Pause system become very difficult to understand, particularly when it comes to movement. What the hell is a 5ft Step in a RTwP game, for example? The concept of rounds/turns becomes completely lost in the system.
Then you have other issues like UI text spam because of the speed of the action. Just go into P:K, throw out an entangle at a group of enemies and watch your screen get filled with barely readable overlapping text "Saving throw Failed!" in the middle of all the chaos. Hell, just try the turn-based mod for P:K, suddenly combat is actually readable and enjoyable.