in response to the OP, 1)because they either did not use it properly 2)and/or have unrealistic expectations of the drug, 3)and/or have used stronger androgens previously.
If you're running it with more powerful androgens (including test) you have to use more of it due to superior AR competition from the other molecule. Also, unless you attached your own ester, you're using undeclynate which provides a very long half-life. You should frontload your dose to get you up and running, then back it down by the start of week 4.