Sentence:  Having had my share of <WSD>ragequitting</WSD> teammates and unfinished campaigns -- I still haven't completed a L4D2 campaign on Expert -- I'll take a positive outlook and say that the complaints about difficulty amount to a longer and taller learning curve, that will give this game a longer lifespan than the first. 
Meaning of the word marked with <WSD> tags:  To quit an online video game in anger.