I am planning to go back home to America, specifically California and of course go home and find a job.
Would it look bad to apply for a job other than teaching to have 2 or more years on your resume? (note: I am not interested in working as a teacher when I get back)
Is it a good/positive experience or a bad or negative experience?
Would future employers view my teaching experiences in Korea as valuable?
Thank you.
Take it from someone who has made "award-winning" resumes and who used to be a hiring manager.
Anytime you apply for a job, and you submit a job application, I encourage you to make sure that the resume is JOB SPECIFIC. If you apply for a Computer Programmer job and you have two years in Korea and a year at McDonalds in high school and mowing your neighbor's lawns, it won't impress me. Your resume has to tell the employer who you are and why they should hire you.
If teaching in Korea relates to the job, you better put it on there. Don't just add a half page explaining how you taught in Korea if you want to be a plumber. Explain what knowledge you have. Explain how you are the guy/gal for the job. Think about it from the hiring manager's point of view. They aren't hiring for an English teacher if you want to be a chocolate candy maker, but if you want to work in sales, it might be worth it. And make sure to phrase your resume to make whatever job relevent to what the job you want is. (i.e., if you want to work in sales and you put your korea experience on it, don't focus so much on the lesson planning aspect, but focus on how you were able to learn another culture and adapt into it and prosper.)
Relevance is key. Don't just slap together a resume. A resume is a one to three page document that explains who you are and why you are important enough for the hiring manager to consider you, if not hire you on the spot.

(If your question is about Korea specifically, like, do employers hate Korea, I don't think so. I can't imagine a good job would say no because you were in Korea)