Here's the summary of why I hate this drama.

1. Let's remember that Saeroyi's mission was to destroy the Jangga company.
2. Let's remember that Saeroyi loves Soo Ah for more than 10 years. So does Soo Ah.
3. Let's remember that this drama is a good drama. It tells us about business and marketing strategy. At least at the early episodes.

At the last episodes:
1. Saeroyi is ACTUALLY failed to destroy Jangga. Soo Ah is the one who destroys the company.
2. Soo Ah had been struggling to find the way to destroy Jangga company stealthily. (this drama doesn't tell you what, how, when, where she did it = plot missing)
3. Soo Ah had been waiting for Saeroyi to destroy Jangga so that she would be able to resign from the company and live happily with Saeroyi after he succeeding his mission.
4. Instead, Saeroyi fell in love with Yi-Seo and dumped Soo Ah, who loves him for FCVKIN YEARS!!!
5. This drama turns out to be "the story of a boss, who dumped his beloved, just to fall in love with a manager"

Conclusion:
I hate Saeroyi so much. It breaks my heart when he dumped Soo Ah. He FAILED to destroy Jangga but he got the company after acquiring it. WHERE'S Soo Ah?
The romance stuff RUINS the plot. The drama went from business-themed drama to sick romance drama.
After all, the conflict resolver is Soo Ah. Saeroyi? He went to a date with Yi-Seo.

PS. Still, I give 5/10 star-rating: 5 for business and marketing stuff. I appreciate that.