Because there isn't enough lag to do most of the orange clips that are used in runs. For most situations, we have alternatives. However, with Any%, they can be harder than the N64 lag-based equivalent.
For example: You normally use lag to enter Angry Aztec Lobby early, however, you cannot really do this on VC. So on VC, we swim through shores whilst DK is at a certain rotation and damage skew on a beaver. Another example is Factory Early to skip the B-Locker. Both with DK and Lanky, you use Orange assistance on N64 to make it easier. However, on VC, with both, you have to do the orangeless method which is more difficult than with Orange Lag. Most notably when trying to perform DK Factory Early
After discussion over the last couple months and a vote amongst community members and the leaderboard moderators, runs on different consoles have been split and are now listed separately under different tabs. The decision included a near-supermajority vote to list the fastest console by default on a