Home made, permanent style wooden stands account for more accidents than those manufactured stands.
They are exposed to all nature has to offer year round. Trees moving and swaying, moisture, heat and cold all take thier toll on the integrity.
They can look perfectly safe, when in fact the wood is significantly weakened. Attachment points, nails, screws, drilled holes all allow moisture to enter the wood, starting the decay process.
Steps and railing are prone to failure, rsulting in falls.
Like mentioned before, for the cost, buy a stand built to TMA specs.
Old decaying stands are eyesores in the woods, and even if you dont use it anymore, someone else could come along and assume it safe, and be seriously injured or killed.