UXMovement

The reason why I think they rejected you is because you are a single founder. That means if you get hit by a bus they're fucked. Whereas, if you had a team or a co-founder the company can still go on without you.

The gutters are way too big for this grid to be effective.

40 px gutters? Are you serious? Gutters should be 10 px minimum and 16 maximum.

I agree that you shouldn't waste time, but I think wireframing is an important and necessary step that shouldn't be avoided or underestimated.

When you go right into high fidelity prototyping you are focusing on many elements of the design simultaneously. You are focusing on the coding (html prototypes), visual design, information architecture (layout, navigation, etc) and you are doing it all at once.

Because of this you end up giving each department bits and pieces of attention, but not enough to see all the details and insights had you focused entirely on each department one-by-one.

I've shot right to hi-fi mockups before and I ended up not seeing a crucial insight in the information architecture side of the project. For me, doing low-fi wireframes and then moving to hi-fi mockups works much better, so I don't overlook certain details and insights.