For most of the stuff you are doing in construct even a laptop with a lousy graphics card is going to work.
Ashley's blog is pointing out Nvidia shortchanging Browsers. But it is mainly limiting our future.
Now I could be wrong if you are designing for the desktop, but if you are aiming to be compatible over the greatest number of devices, you should be fine.
I just bought a Surface Pro tablet I plan on using for Construct2, (and pressure sensitive sketching,) and it has the same intel 4000 graphics processor Ashley's laptop falls back to. So far it's working fine.
(I would recommend a keyboard though, ugh.)