Since the topic has drifted away from locating models with side patios and into why would someone want a side patio.
I can imagine two reasons right off the bat. The are people who might have limited mobility and find the stairs to be challenging. Maybe there is a wheelchair bound child, spouse, or elderly parent who likes to camp. Mom can roll her wheelchair or her walker out onto the patio and enjoy the outdoors.
A second reason might be someone who regularly camps on the beach or in the desert for the view but doesn't like the tracked in sand. I camp in the desert almost exclusively and I do not need a toyhauler. So the option of converting the ramp into a patio is not available.
So while I personally do not need a side patio; I can imagine where someone, especially a new RV buyer, could think a one was a good idea. But the fact that not many manufacturers offer the option speaks volumes to the usefulness of such a an option.