If you want to ascertain whether it was made obligatory by Allah or scholars then I can direct you to this:
“Obey Allah, and obey the Messenger, and beware (of evil): if ye do turn back, know ye that it is Our Messenger’s duty to proclaim (the Message) in the clearest manner”. (5: 92)
“O ye who believe! obey Allah, and obey the Messenger, and those charged with authority among you. If ye differ in anything among yourselves, refer it to Allah and His Messenger, if ye do believe in Allah and the Last Day: that is best, and most suitable for final determination.” (4: 59).
“Say: “Obey Allah, and obey the Messenger: but if ye turn away, he is only responsible for the duty placed on him and ye for that placed on you. If ye obey him, ye shall be on right guidance.”(24: 54).
“And whoever obeys Allâh and His Messenger, Allâh shall admit him in the Gardens underneath which rivers flow.” (4:13)
“And we sent no messenger, but that he should be obeyed by the leave of Allâh.” (4:64)
Now these are Quranic ayah. There are many more and they all say the same thing: If you are to obey ALLAH then you should obey the PROPHET.
Now everyone knows the sunnah of the prophet pbuh regarding hijab. At the time of the prophet pbuh (and this is historical fact) when the verses of hijab were revealed the women and the wives of the prophet pbuh ALL covered their heads to show that they were following the commandment of hijab. Now if they were being too extreme the prophet pbuh would have told them.
For example there are hadith where the prophet pbuh told companions not to fast every day or pray all night because Allah wishes for us ease.
So if you look at it there then its not scholarly opinion at all. Its actually the opinion of the prophet pbuh. And the commandment of the prophet should be obeyed if you are to obey Allah. As for the people who were practising wrong things for centuries I do agree with that. However the people who practised and prescribed hijab were the sahaba, the tabieen and the four imams. Now these people were on a higher level of faith than those of us today. And the sahaba, tabieen and imams would NEVER have presumed to make judgement which was against prophetic tradition or teaching. They were and are the best of Muslims.
Now whether this is enough evidence for you I don’t know but all I can say is those people were better Muslims, better educated in deen and followed Islam in a better way than the Muslims of today. If that is still not good enough for you then in the end Allah knows best.
I also found this:
It was narrated that ‘Aa’ishah (may Allaah be pleased with her) said: “The riders used to pass by us when we were with the Messenger of Allaah (S) in ihraam, and when they drew near to us we would lower our jilbabs from our heads over our faces, then when they had passed we would uncover them again.
Narrated by Abu Dawood, 1833; Ibn Maajah, 2935; classed as saheeh by Ibn Khuzaymah (4,203) and by al-Albaani in Kitaab Jilbaab al-Mar’ah al-Muslimah.
So from this hadith it clearly states that the jilbab was used to cover their heads. That’s a sahih hadith. There was another one I read that I can’t find now that stated that the believing women wore the jilbab in a way that it looked like crows were on their heads. Which is another example of the head covering. If I find it I’ll post it.