From a management point of view, you want to know that you are getting the top return on investment for all of your IT efforts. Scrum makes this clear, visible and in the control of the product owner, who is often funding the effort.
But what about all of the other time and effort by IT personnel whom are not on agile projects, those who are most often "putting out fires" or working on short-notice market-driven system changes? Without a lightweight method to track these efforts, funding could be misspent and neither CIO's nor CEO's would know. Worse than money wasted on effort not making a difference, it is money that could have been spent on something that would have improved the company and\or IT.
This IT request tracking should give visibility to requests, timeframes, the requestor, estimated effort and status. It should be visible to all IT and company management and proactively alert key stakeholders, and also provide summary reports of effort so that management can regularly easily see a high-level view of all effort and knows how money is being spent.
