Remember the days of internet text browsers? There were no pictures, video clips or even colorful fonts to catch the users’ eye. Users had to read through lines and lines of plain text just to find a section of their interest. Unimaginable isn't it? Internet wouldn't quite have been the same without the advent of GUI based browsers.
In some respects, we can draw parallels between the Internet and design/verification worlds. DV engineers have, so far, been debugging VIP issues with the help of log files. The log files are analogous to text browsers, as DV engineers have to sift through thousands of lines of unformatted and unstructured text to find relevant information that can help identify the root cause of a failure. Wouldn't it be so much better if there were GUI based tools that could display interface and transaction level information in a protocol defined format? Just as the full power of the Internet would not have been unleashed if not for GUI browsers, the true potential of Verification IPs will perhaps never be realized without GUI protocol analyzers.