A transistor with a certain part number can be very sensitive and turn on with a low base current but another transistor with the same part number and made by the same company could be weak and not sensitive so it needs the amount of base current that is shown on its datasheet: 1/10th the collector current.
If you make every circuit use a base current 1/10th the collector current then all your circuits will work, not just the ones that have very sensitive transistors. Maybe you won't have any very sensitive transistors.