You will always find people saying remedies don't work, Yes, its true — It is not meant to work for all, as this is like I took a particular medicine for stomach infection but never recovered from diseases but someone else did in recovered in two days.
As another person might not have infection as bad as yours as remedies are extensions to increase energies in certain area of life to help you get cured.
Such as when you eat food everyday — It is supposed to provide you nutrition and keep you safe from all diseases by building up immunity but still time comes that due to deficiency of certain mineral you fall sick and that is compensated by providing you medicines.
Medicines will be ineffective in case your diet is not proper and you continue with bad eating habits, similarly while prescribing remedies astrologers are assuming that you are a good person, who follows the norms of life and what is expected of you in each Rashi.
Such as sign of Taurus represents family, Speech and earning capacity and astrologers are assuming that you are a good person who never speak ill of others, provide food and shelter to everyone under you, take care of family members and do not waste food or disrespect any race, religion or any creed.
Then astrologer provides you remedy of feeding a bull everyday as malefic in taurus can hamper your married life and progeny but you need to get basics right first and see what you can improve in life and then go for remedies, A person who is not willing to correct himself after learning Jyotish and only speak ill of others is not worth doing any remedy.
The whole purpose of Jyotish is look inside and find problems rather than fixing the outside world.