Options are good. I personally play with a controller, so I'm still having to scroll between abilities regardless of how many bars I can see. A keyboard user would probably have to press other buttons (like you do for macros) to get use out of this idea, or scroll up/down to chose which skill bar/row to use before hitting the key. It only really solves things for a mouse user.

But if that's how you play and it makes your life easier, then there's really not a problem. It's already been stated that they want to improve gameplay for all types of users, be they controller or keyboard with or without mouse. As long as said option is an option, and not enforced as the standard from which all others are options, it's all good regardless of whether or not that play style is optimal.