Simple. When a large percentage of voters are sick and tired of the existing political culture, and view its "rules" as opposed to their interests, then taking advantage of the rules tends to annoy the voters.
Remember the House banking scandal? The House members who were using that bank were following the rules, but once the public learned what the "rules" were they weren't too happy about them. And a number of politicians found themselves in political hot water.
Annoying voters is rarely a good way to win election.
Sadly, the voters you refer to don't have enough sense to TAKE IT OUT ON THE PEOPLE WHO MADE THOSE RULES, and not the one who went by them.
If Cruz had broken the rules, then they'd bitch about that.
Let's call a spade a spade. Donald trump didn't see a big enough profit margin in getting a ground game going in the Western states, and didn't put forth the effort.
Voters in those states may not be happy with the lack of caucus or primary, but that is an issue to take up with the RNC. The candidates didn't have crap to do with that.
Trump put forth no effort there, and got no results. I guess we were all supposed to be impressed by his money or star power or something (Yawn).
When that didn't work, the Trump marketing department went into full twitter fit and said Cruz (oops, "Lyin' Ted", I left out the standard pejorative) was cheating because those states didn't fall on their faces and worship the Donald, even though he has said the states were "not worth the effort".
There are all sorts of people all over, but most of the salt-of-the-Earth folks I know out here would be singularly unimpressed with the Donald at that point, or just flat disgusted.
What kind of president is that man going to make if he can't own the results of his own decisions?
Maybe he can blame the video.