Follow the money. Not everything is attributed to a cause, reason, or support.
Publicity on these kind of matters doesn't mean that we, the unbathed masses, will ever be privileged to know the facts behind the statements.
As for Trump's comment (from his iPhone), it is just normal politics.
This last weekend, reviewed an article.
It basically showed the demographics for Apple iPhone users.
The demographic profile infers that the type of people who own iPhone won't vote for Trump. So, Trump lost very little or nothing.
The demographics also indicate that Trump supporters (most Android users) would probably laugh at jokes made about iPhone owners. There are so many jokes about iPhone users from South Park cartoons to stand-up comedians. Nothing new, just a profile.
The point is, Trump once again got free national publicity. The iPhone owners that were not amused would not be Trump supporters anyway. Those that don't like iPhone users enjoyed the jab at Apple.
My guess is that Trump, like most people who run for office, understands marketing 101.
This is no different than any political figure getting free publicity by saying "<blank> owners (or users) are <fill in the blank>". It gets free press, it doesn't drive away their own supporters. Yes, every situation is different and while it rhymes with other situations. The News media... they sold a lot more advertisement by adding hype.