Sprint reviews are a fundamentally important–and often ignored–element of a team using scrum. While it may be easy for teams to do a daily stand-up or sprint planning, it's much less likely that teams will properly complete sprint reviews. The reason being that, in “the heat of battle” (as blog author Ian Mitchell puts it), the sprint review is more likely to be sacrificed than the easier stand-up meeting.
That being what it is, Mitchell makes sure that the sprint review is a requirement for any sprint–as it gives an opportunity for stakeholders to see what work is being done and still needs completed, provides an opportunity for the team to learn from current successes and mistakes, and review what work remains in the product backlog. There's a lot going on within a sprint review, and this is one of the reasons that it gets tossed out when time seems to be disappearing. As reviews happen at the end of a Sprint, team members are likely working very hard at completing work. Furthermore, reviews show what work hasn't been done yet, which can make newer teams feel as though they are shining a light on their shortcomings. Finally, reviews take time to prepare for, and that's time that could easily seem more valuable in working on the backlog or the Sprint deliverables.