Gone are the days when a website was just viewed on a PC, Mac or laptop.
Mobile views now make up between 40% and 50% depending on who's statisitics you believe. Either way thats a big number to just ignore.
To get the best user experience from a responsive website, it needs to change the way it looks based on how it is being viewed. The site even needs to change how it looks depenant on the oreintation of the device, as mobiles and tablets get used at all sorts of angles.
In short, viewing a website on a mobile phone should be a very different experience to viewing the same website on a laptop, pc, or tablet.
If your site looks the same on every device, just a different size, then we need to talk and show you how you could be benefiting from the huge mobile internet market.