The concept of taqleed started with the following of imams and particular religious personalities. Like today, a huge number of people call themselves hanafis, some say there are shafaities, some are hanbalis and some are malikis, some say they are raza khanis while some go to the extreme and follow even kafirs like bhuly shah. These people derive their religion not mainly from Quran and sunnah, bus they like to get the idea of islam from the books written by these people mentioned above. But Quran says that it is the easiest book to follow and to understand, how come the writings of these people who were humans like us (even pious but still humans) can be easy!
ALLAH swt says in Quran:
Al-Quran 44:58
Verily, We have made this (Quran) easy, in thy tongue, in order that they may give heed.
Al-Quran 54:17
And We have indeed made the Quran easy to understand and remember: then is there any that will receive admonition?
Al-Quran 54:022
But We have indeed made the Quran easy to understand and remember: then is there any that will receive admonition?
Al-Quran 54:32
And We have indeed made the Quran easy to understand and remember: then is there any that will receive admonition?
Al-Quran 54:40
And We have indeed made the Quran easy to understand and remember: then is there any that will receive admonition?
And there are many other verses that speak the same stuff, why not to get guidance from Quran first! By saying that to follow Quran and sunnah does not mean that we are degrading the authentic persons. The whole point in making the statement is to realize that what ALLAH swt revealed and taught us through Muhammad s.a.w.w is flawless and there are no mistakes and errors in that work. But all the work done by humans is ought to be flawed because we ourselves are not perfect, if we are not perfect how can our ideas be perfect?
We should give weight to the saying of every pious person because a man of knowledge knows much more than us, but we should not follow any person blindly because we do not know where a person goes wrong.
ALLAH swt has given us permission to do ijtehad, qiyas and ijma but it is also made clear on us that ulema may reach a wrong decision because they are not the ultimate source of knowledge. if they go wrong with the clear intentions there will be no sin on them, but if they go wrong deliberately like some ulema ar doing, they will be held accountable and the followers of these people will also receive the same gunnah.
ALLAH swt says in Quran
A-Quran 17:36
"Do not take a stand about anything you have no knowledge of. Indeed, the ears the eyes and the heart have all to render an account."
So, to accept any saying without verifying it or thinking about it means that we are going against Quran. But we see some brave people abusing others and calling others kafirs openly on the grounds of what their imams have said.
In another place ALLAH swt said:
Al-Quran 9:031
"Instead of Allah they accepted their scholars, their monks, and (above all) Jesus son of Mary, to be their gods. In fact, they were commanded to worship (none but) the One (true) God. There is no god but He. Exalted is He, far above the partners they associate with Him."
Do not we see aall this happening the same today, when people go to mazars and ask the dead people buried there for help but they forget that ALLAH is very near to them even from their jugular vein? This is all shirk and sin, we must not only stop ourselves from blindly following even a pious and most knowledgeable person but also, we should not argue on what we do not have knowledge. To understand din, the best sources are Quran and Sunnah.