There is PLENTY of reason! The right tool for the right job and all that.
OOP has no place in the embedded world - nowhere nearly enough available resources. Besides, there is a reason it is called C
plus plus, it's an extension to C, though enough different to be a whole new language.
Once you learn programming concepts (Object Oriented Programming OOP is only one concept, event driven programming is another, and structured programming is yet another), language just becomes a matter of syntax. That doesn't mean that proficiency with one language grants you proficiency with another, but learning language nuances is much easier than learning programming concepts.
What are your programming goals? If you are a novice, C/C++ aren't the best languages to start from without a teacher to help guide you. They have some really abstract concepts that are difficult to grasp, and it's easy to develop sloppy programming habits if you aren't careful. Your best bet if you are starting out is to have a project in mind and try to find a similar project and learn the language that was done in. Web pages written in JavaScript (.jsp) or ActiveX (.asp) are decent to start with as there are plenty of examples. Visual Basic and Java are good as well.