Many coaches insist on e4, but there are MANY traps and tricks and pitfalls with e4.
With d4 (Queen Pawn), a beginner can bypass most tricks and play a solid game if taught the opening correctly.
I feel the need to comment on this.
If taught ANY opening correctly, a player should be able to "bypass most tricks and play a solid game".
Learning to play the opening phase well and reach a playable middle-game is not some rare event—and it's certainly not something that only system openings provide. A beginner can learn to play any opening with proficiency.
That said, it's great that you believe in the London, and it's certainly a playable opening at any level. But to argue that beginners should learn it because it avoids many opening pitfalls is too narrow of a reason for promoting it (and kind of misses the point of good chess instruction for beginners in general).
The reason e4 games are taught to beginners goes beyond the concern about "pitfalls"—it has more to do with exposing the student to common tactical (and even positional) ideas, to help them learn how to think at the board.
With the Ruy Lopez, for example, white is learning, right from the beginning, the fundamentals of tactical play. After 1...e5, white develops his knight to f3, which both develops a piece and attacks black's undefended central pawn. After black defends with ...Nc6, white plays his bishop to b5—attacking the defender of the pawn.
This line is instructive—it teaches the beginner how to think at the board with direct, logical moves.
The London System has an appealing "safeness" to it, yes, but the moves are far less instructive. Are they practical? Sure. Instructive? Not so much, not when comparing it to e4 games.
If one's really dead-set on promoting the London, I'd save it for the intermediate level, after the student has benefited from the instructional nature of e4 games.
This is the same way I plan to teach my son (when he's old enough. He's still a bit young at the moment)—by exposing him to the ideas of e4 chess. Then, when he's ready to branch out, introducing him to the non-e4 systems. But only after. Not before.
I vote for 1. d4
to survive 1. e4 is in large part just memorization to avoid tricks, traps, and quick mates... or worse yet trying to use them yourself, which probably won't work often (since everyone else is learning them) and then and just leave you with a bad position. I think 1. d4 is a better way to just learn how pieces fit together and the overall flow of the game, by playing games with slower, more subtle development, attack, defense, and king safety all taken together
To "survive" 1.e4 is to stop blundering. That's all it is. Traps only work if you blunder. They're traps not forced losses. There are very few positions like say, the fried liver where you can easily just fall into a dangerous position without doing anything that looks obviously bad. But there are traps after 1.d4.
b4
The knight on g5 is hanging.