I think the general sentiment is, review the full game. Destiny was designed with an endgame loot grind, climaxing with the Raid. A critique of the endgame content could be that it's too inaccessible, or too hardcore, or badly designed, or whatever. But requesting that reviewers take into account the full scope of the game strikes me as reasonable. (Though Bungie did themselves no favors in that department by locking it off for a week.)
I've got to say, selling a game in a way which specifically encouraged pre-orders, let alone normal release-day buys, in a form that's unfair to assess critically is simply unacceptable to me. Even with this said, the vast majority of the reviews I encountered didn't fall victim to that pitfall of predicating their criticism on just having seen part of the game.