I can see where Trump supporters would have wanted him to be more explicit in his support of Trump, but I took the whole speech as at least a tacit support of Trump's candidacy.
His whole speech was one advocating issues that were closely aligned with those of Trump and adversarial to those of Clinton & he had started it all off with congratulations to Trump.
Had some of the delegates not made an issue of it I wouldn't even have noticed that he hadn't explicitly stated his support of Trump. Making a big issue out of it was like picking at a scab and is what in fact drew blood.
Also, all of the talk about Cruz not honoring his pledge to back the nominee seems overblown given:
Kasich didn't come to the convention even though it was in his own state and governors have gone to the conventions of opposing parties just out of a sense of duty and hospitality.
Marco Rubio apparently didn't show up for the convention & sent a video instead
Carly Fiorina didn't show up
Bobby Jindal didn't show up
Jeb Bush not only didn't show up but has been repeatedly criticizing Trump since he dropped out
Not sure about Pitaki, Santorum, Walker or others, but they may not have still been around when "the pledge" was an issue.
I think I think that the angst is also a bit hypocritical given that Donald Trump himself had said that he was not going to honor the pledge:
Trump rescinds pledge to back Republican nominee; Cruz, Kasich refuse to commit support
http://www.foxnews.com/politics/2016/03/30/trump-rescinds-pledge-to-back-republican-nominee-cruz-kasich-refuse-to-commit-support.html
Donald Trump said Tuesday that he would no longer honor his pledge to support the eventual Republican nominee for president, while fellow candidates Ted Cruz and John Kasich refused to say whether they would back the party's pick.
All three GOP contenders appeared at a CNN town hall in Milwaukee one week before Wisconsin's April 5 primary.
When asked if he would keep the pledge he signed last September, Trump responded "No, I won’t." The real estate mogul explained that he was taking back the pledge because, "I have been treated very unfairly," and listed the Republican National Committee and party establishment among those he believes have wronged him.
Cruz, who is running second to Trump in the delegate race, shrugged off the question of whether he would support Trump in November, saying "Donald is not going to be the GOP nominee. We're going to beat him." The Texas senator added that nominating Trump "would be an absolute train wreck" and "would hand the general election to Hillary Clinton."
Trump, who followed Cruz on the town hall stage, said he didn't need a promise of support from Cruz.
"He doesn’t have to support me," he said.