Hi there,
These days, most of the sites are ran on some sort of CMS or ecommerce platform and/or created using a PHP or ASP instead of static HTML and the pages that you're looking at is a dynamically created output page, the code itself resides on a totally different page that you(the regular visitor) can not view, you can only view the end result. If it was just a regular static HTML page then it would be possible.
Judging by the prices on these sites, they do more of a quick turnaround then quality work. I don't think they would spend their time on optimizing any code, their job is to make a quick buck... I always refer to a saying "what you pay is what you get!"
I think this is what matters:
Your images, are they optimized for the web and don't have any visible distortion, are they small in size?
Your CSS, is it clean? Is it 5000 lines long and 80% of it never used?
Wordpress SEO plugin: either Yoast or All in one SEO
Compression on the server
Minimize javascript
Avoid Flash
Good, Reliable & fast hosting
Hope this somewhat helps...