It's a fine line between "minimal and designery" and "understyled". I think this falls slightly to the wrong side. Also, the icon thing encourages people to check the most number of boxes, even if they're not skilled there. This is reasonable and something lots of devs do, but it will hurt your appearance to people who hire. Everyone I've ever talked to about hiring developers has an opinion somewhere in the realm of…
As for the icons, my theory is that devs are free to add whatever skills they want to their own portfolio or resumé anyway, but they're going to ultimately be responsible for demonstrating that knowledge to employers, clients, etc, so it probably wouldn't be beneficial to them to exaggerate their skills. I do see your point though.