That’s a bit of a stretch.
The current version of HTML5 Boilerplate includes several things in the header that probably aren’t exactly what you want, particularly if you’re supporting mobile devices.
It loads 4 distinct JS files. One of those is Modernizr, which is loaded at the top of the page and will therefore block, and there’s a custom class on the HTML element to go with it.
It loads 2 distinct CSS files.
It inherently has potential security and privacy issues that come from using any third party servers, in this case Google Analytics and attempting to load jQuery from their CDN.
Likewise, it has dependencies on some third party scripts, both Modernizr and the ones for Google.
And it contains an unprofessional nag message for users of IE8.
This is not a criticism of HTML5 Boilerplate. All of the defaults mentioned above might be a good fit for some projects, even many projects. However, none of them will be suitable for all projects, so the moment you start from HTML5 Boilerplate you almost certainly have some technical debt to pay off, just like any other template or framework or scaffolding system.