|If anything I would expect drives (especially optical drives) to go bad more often than other components in a computer. Mainly because they are mechanical devices. Other components are usually just circuit boards and chips. Hard drives are assembled in a dust-free environment and sealed, plus they use sophisticated electronics (magnetics) for the physical movement. However, optical drives are exposed to the elements every time you insert a disc and are, for the most part, completely mechanical. It is built using plastic gears and rubber "bands". Plus they are expected to operate at very high speeds. Disks with cracks have been known to "explode" when used in high-speed drives.|
All this being said, I have had maybe 2 drives go bad in the last 10 years out of maybe a dozen or more drives. I do have problems from time to time, but have always been able to fix them. Although the poster above discourages it, I have been able to correct many problems by opening up the drive. Most times it's just a dirty lens (I don't find the lens cleaners effective). However, I have also had an issue where the rubber band had come off the pully and other mechanical parts were "out of whack".
If you are a smoker or a pet owner (or have other contaminants in the area where the PC is operated - e.g. wood burning fireplace, kitchen, etc) then you could have drives go bad more frequently.