Let be clear here. The fact that Muse does not do "responsive" design does not make it an AMATEUR program. I never said anything like that. I said it is not designed for "web" professionals. It's market is "print" professionals and people who don't want to do code. It builds "professional-looking" web pages. Here is the exact text from the Adobe website for Muse:
Create unique desktop, tablet, and smartphone versions of your sites. Easily add touch-enabled functionality, such as slideshows, using drag-and-drop widgets. Set up icons to dial a number, bring up maps, and open email.
What is inaccurate about this? Where does it say that it is intended for use by Web Professionals?
The code written by Muse is based on Web standards. But there are lots of standards. HTML5 and CSS3 are still not adopted as the industry standards, yet. These are still drafts and changes are still being promulgated. I have never heard an Adobe evangelist say that Muse is intended for everyone. It's aimed at InDesign users, and it's interface and workflow is very similar. Why? Because it was developed by the InDesign engineers.
Don't use Muse if you want to edit the code or want responsive pages. For the time being, it only does adaptive design. 
An example of people using the wrong product for the wrong purpose...