Very low appearance of the silk touch enchantment

As the title states, the appearance rate of the silk touch enchantment has been greatly reduced in 1.14 in both pickaxes and books, almost to the point of absurdity. Across 150 or so books I tested I got 0 silk touch enchantments, and across roughly 100 diamond pickaxes I got around 3. I did not test shovels, though I have no reason to believe it it would be any different than the apparent 2% rate. I am aware that enchanting has been nerfed in 1.14, but the silk touch drop rates seems a step beyond what has happened to everything else. From what I can tell rarer enchantments like fortune have been reduced by around half their original drop rate, not the 90% drop in rates that silk touch has experienced. I do not know if this is intended, but I cannot think of a reason for silk touch specifically to receive a much larger nerf than other enchantments.