yes, I guess for this Iqbal said,
Thay tu wh abaa tumharay tum kya ho
haath per haath dharay muntazir-e-farda ho.
What is Mehdi, he will be a person who will stand for his believes, and who will openly work/fight for the right of weak and for the Justice.
This is what quran is teaching isn’t it. we as muslims do not want to act on quran as it will be against our interest of Nafs, so we have developed a concept that there is one more promised one, who will come and lead us to peace and justice.
Funny Isn’t it? We have the book, we have clear orders, and we have a role model, and with all this we are still waiting for someone to come and teach us or implement the orders of Allah all mighty? then what is our duty, just to wait? and we will get jannah for this? it is pathetic.