Dropping Prepositions

It seems to be acceptable in British English, as witness:

Donald Trump received a glittering welcome from leaders in Saudi Arabia on the first day of his first international tour, as the two countries agreed a series of military deals worth nearly $110bn (£85bn).

That offends my linguistic sensibilities. If I were editor, I would expend some red ink. One does not agree X, one agrees to X, or upon X.  If you make a proposal, I may reject it, but if I agree, I agree to it; I don't agree it.

Stateside one often hears sentences like 'She will graduate high school in June.'  The meaning is clear, but the style is bad. One graduates from high school.

I am just reporting on how I prefer to write and speak. But if a competent user of English reports on how he prefers to write and speak, then the report has normative import.

The Lousy Linguist has more data on British English if this topic is of interest. And even if it isn't.

Addendum

An equal but opposite stylistic infelicity is the adding of unnecessary prepositions. For example, 'Where's your car at?' instead of 'Where's your car?'