Is Salesforce really that bad? =( Curious to hear people's thoughts on it - particularly on their Service Cloud product? What are the issues people are having?

Is Salesforce really that bad? =( Curious to hear people's thoughts on it - particularly on their Service Cloud product? What are the issues people are having? Also, can you extend it easily, or code plugins (or whatever they are) for it easily? (If I have to deal with it, keen to hear what I may be in for).