Yes, this is bad. Shame on Trump for doing it.
How do they enforce a rule that applies to what a financial planner has in mind?
It's a long convoluted process, but tl;dr
1) Client signs up with advisor and fills out a form outlining their investment objectives.
2) If advisor makes trades that do not meet said objectives, or chooses selects the higher commission option between two investments that both meet their objectives, they fail the standard.
3) If a client complains, one compares trades, statements and commission structures to examine if the advisor failed the standard.