Empire is the exception, not the norm. No other show is rising like Empire, not just HTGAWM.
I'd also say Empire appeals to a wider cross-section of people due to the subject matter. Pretty much the only show I can think of that straight men, straight women, gay men, and gay women are equally excited about.
This. Empire is just like Dynasty/Dallas where it made it comfortable for everyone to watch. These kinds of shows are straight up Soap Operas that hit every demo. They have rugged guys and beautiful women to make the straight guys comfortable. Shady women, soapy drama, and hunky guys for the women and gays. Shows like these thrive when they are done correctly because there premise is simple and it is easy to jump into it and take in the information.