>>>>It seems most of the stairs are made with leaves which can be harvested extremely quickly with shears at "20 blocks per second" yielding 238 blocks, 3.7 stacks, per shear. Since leaves are such an easy material to gather for only 2 iron, the restriction of the use of shears or breaking leaf blocks could solve the problem or at least make it more difficult for players to gather materials to build their platforms.
>>>>Now we cannot ban the practice of sky bases outright since the players spent their time to fortify their area with the strategic strength of stairs. If i saw a person who made a sky base out of wood or stone i would accept that since they made significant effort into gathering those materials. Gathering 1 log takes 3 seconds to gather with just your fist and when using a wooden axe increases the log gathering to 1 per 1.5 seconds. The amount of logs gathered in a minute is significantly less than the amount of leaves you can gather in a minute and provides a balance to the height you can get to in a single minute.
(These numbers are ideals and are not adding time to find the materials or replacing broken tools.)
Gathering logs with your fist in a minute yields 20 logs or 80 planks[1.25 stacks]. (1 log / 3 seconds)
Gathering logs with a wooden axe in a minute yields 40 logs or 160 planks[2.5 stacks]. (1 log / 1.5 seconds)
Gathering leaves with shears in a minute yields 1200 leaf blocks[18.75 stacks]. (20 leaf blocks / 1 second)
>>>>1200 blocks per minute, even if that is an ideal, is completely crazy and stupid how many blocks you can get for such little effort to create the sky bases. Something doesn't need to be done to the platforms themselves, but the materials used to make them. With the removal of the use of leaves we will probably see lower platforms which makes them more accessible to hunters and a better balance than the high slaughter house they are now.
>>>>I believe the gathering of leaves can be easily controlled more easily by staff since the blocks broken can be controlled on a map to map basis.
Sources:
http://www.minecraftwiki.net/wiki/Digging#Blocks_by_hardness
http://www.minecraftwiki.net/wiki/Shears#Speed_and_durability