To my mind there are quite a few aspects to what , despite appearances, is actually quite a complex question.

On a very basic level it must be acknowledged that there is only so much time in an educational syllabus to cover a lot of history. In the UK , at least from my experience, the Romans were only covered in primary school in any detail and this was only the basics in a very general sense with little complexity (i.e Roman roads, emperors, the Roman period in Britain) Nations often like to cram as much of their national history as possible into learning as a recognition of their own language, culture and history. As such, unfortunately this often means that Byzantine history is sidelined. As a historian it pains me to say it but if you are in the United States, for example, it makes sense from an educational perspective to trace the more relevant historical journey from Western Europe to the United States of today rather than focus on the East. It can often simply be a matter of time and focus and the limited amount of time dedicated to studying History in modern educational systems.

I would argue that Late Antiquity in general is criminally underrated within the education systems of the Western world. There is a prevailing idea that the Roman Empire 'fell' in 476 and that was the end of it; many school children would be taught this and not be made aware of the continuation in the East at all. In the context of taught history in the UK, for example, it is much easier for narrative purposes to end the Roman period at 476 than to explain the Byzantine state up to 1453.

Petran79 is quite correct that the Byzantine East was regarded with contempt by contemporary writers and was by historians well into the 20th century. Byzantium was often labelled as a 'caricature'; a failed, despotic pale imitation of the united Roman Empire of Augustus or the moral, republicanism of the Roman Republic. Edward Gibbon, in his seminal work 'The History of the Decline and Fall of the Roman Empire,' famously quoted that 'of that Byzantine empire, the universal verdict of history is that it constitutes without exception the most despicable and debased form civilisation has ever assumed.' Gibbon and his peers were influenced by the values and prejudices of the European Enlightenment which sought to ignore the cultural achievements of the Byzantines due to their perceived decadence and moral failings. This negative image of the Byzantines became widespread through the increasingly moral and Eurocentric Victorian period and persisted until the 1970s. Hegel described the Byzantine realm as 'a disgusting picture of imbecility; wretched, nay insane.' Even statesmen came to sight Byzantium as an example to avoid, with Napoleon pleading 'Let us not follow the example of the Byzantine Empire.. to become the laughing stock of prosperity.' These ideas would not be challenged on a wide scale until the publication of works by historians such as Peter Brown in the early 1970s. The dismissal of Byzantium begun by Gibbon has been pervasive and has certainly influenced how worthy many thought the Byzantine period was of any form of study.

The final aspect of the lack of Byzantine Studies in education is the simple complexity of the issues under discussion. Judith Herren, a Professor of Byzantine Studies at Kings College, points out using a great anecdote that for the ordinary person Byzantine history can come across as complicated and inaccessible. She recounts two workmen knocking on her office door and asking 'What is Byzantine history?.' She struggled to sum it up in ten minutes, and as she did so she was glad to discover that the two men were absolutely fascinated. The comment the men made ended with them asking 'Why don't you write about Byzantine history for us?. Countless books have been written by specialist academics on Byzantium but there are often too long, too complex or too specialised to be marketed to a wider audience.