I assure you, Quality Score exists. If you want to succeed in AdWords, you need to care about Quality Score. But how far do you take that?
I like to tell people this: Forget about Quality Score (QS), and spend your time worrying about quality, period. Use proper AdWords hygiene for Quality Score, but put your best efforts into real quality. Why? Because Google isn't human, you are.
You are the judge of quality.
You are a human, living in (likely) North America, speaking English. You've immersed yourself in this culture for a long, long time. Your BS-detector can sense a Nigerian scam before you even open an email. You are very well equipped to judge your own AdWords for quality.
Look at your queries. Are they whole searches or partial ones. Fully on-target, or near-misses? Some industries are so crowded, that you absolutely must have every keyword be fully-targeted. For example "buy books about AdWords" is more focused than "books about AdWords". The word "buy" adds a tremendous amount of meaning to the search.
Quality Score isn't everything.
Your industry is different, and nuanced. You understand it, likely better than anyone else. Make sure your own feelings about keywords and queries are included in decisions about quality. AdWords isn't a meaningless game of math. It's a complex cultural marketplace.