Am I wrong to think this way?

Yes.

From a modern perspective, you're not exactly wrong in your assessment. Personally, I really like the fact that I can can say what I like about religion without being afraid of being set on fire, and penicillin is really the bee's knees.

Leaving aside the fact that a medieval person would consider my agnosticism a terrible negative and penicillin irrelevant since I would be doomed to eternal death in Hell, the largest problem of your thought process has to do with scope. From that same modern perspective of what is good and bad, literally every period of human history that is not the present is horribly dark and depressing.

So, what does it say about you that you've chosen to focus on medieval Europe as particularly egregious? To me, it reveals that you have some fairly deep seated biases and preconceptions that you're not aware of, and which frame and manipulate your world view subconsciously.

The ideal historian does not try to render judgment upon the past, but rather attempts to understand the people of the past as they might have understood themselves. The former imposes the present upon the past, while the latter provides understanding.

It should be further noted that, for many people, the Middle Ages were a better time to be alive than some others that have gotten better press.

Take serfdom, which we assume to be a very bad way of life indeed. You were tied to the land, owed labor and all sorts of taxes and fees to a lord, and even had to ask his permission to marry a woman from another manor. But when compared to Roman and later Frankish agricultural slavery, which serfdom replaced, it seems a positive delight. Serfs could own property; slaves could not. Serfs were allowed private lives in their off-time. The lord of a serf did not have the power of life and death, at least not in theory. Most importantly, a community of serfs could readily maintain their population over generations. Roman agricultural slaves were housed in barracks, fed by their owner, allowed no privacy, and though some may have reproduced, maintaining family conditions seems to have been impossible, and they died out over time due to the harshness of the conditions, requiring a steady supply of foreign slaves.

Yet Rome is reckoned a golden age, because of the things that a very small part of the population was engaged with. It wasn't necessarily pleasant for many, even most of the Roman world, but it has left a rather impressive legacy that blinds us to the more negative aspects of life. The Middle Ages, on the other hand, suffers in public opinion because first, it was a rural rather than urban age, and left little written records, and second, because it preceded the Italian Renaissance. Ignoring the fact that there had been previous rebirths in learning (the Carolingian Renaissance, the 13th Century Renaissance), these new learned men decided everything that had come after Rome but before them was a period without light, a literal dark age. Though the Italian Renaissance was a great step forward for mankind, we shouldn't assume that they were right about most, or even much, history. In this case, they display great prejudice.

Another way to reconsider your perspective is to think about the period that follows immediately the Middle Ages.

• We like to think about the Renaissance as a nice phenomenon which strictly fits our chronological boundaries; in fact, it is important to note that many of its personages were, if such a word has a meaning, “medieval”. Dante Alighieri was born in 1265, Boccacio wrote about the infamous Black Plague and Petrarch worked for the popes in Avignon. Not to mention the importance of the medieval universities.

• I would probably prefer to live in the 12th or 13th than in the 16th or 17th centuries. The Reformation and the European wars of religions (including the Thirty Years' War, arguably one of the most violent conflicts between the Antiquity and the 19th century; some people have even said that it was Europe's first total war) happened during this period; the Spanish Inquisition was created then and had its most active years (though interesting works of revision have been done on this subject); and witch-hunting is a purely modern idea (with a high-point in the 17th c.).

• Economically speaking, growth has been basically non-existent before the 18th century; living conditions are not likely to be extraordinary different for most people between 1200 and 1700 AD, even though there might have been some improvements over time (but actually, not that much: European economy was so successful in the high Middle Ages that by 1300, it was almost overpopulated. After the Plague, some places would not return to their initial population levels until the 18th century!).