If most of the top rides go to the standby pass virtual queue, it won't be, especially since you can only be in one at once.
If it's noon and you're at Hollywood Studios and have a standby pass for Tower of Terror at 3:30, and Slinky Dog, Smugglers Run, Star Tours, MMRR, and Rock N Roller Coaster have also all activated the standby pass system... you don't have a ton of options left for how to spend those 3 and a half hours.
At first glance that seems like less of an issue at the Magic Kingdom. However, if all the headliners there are in standby pass mode, it will just push everyone to the lesser attractions and you'll end up with very long lines for rides like Winnie the Pooh and Little Mermaid because people have nowhere else to go.