It's a good suggestion. I have the same issue. But I suspect that the space is needed for those who want to have the icon + name option. Ultimately, it is not that big of a deal. More of a cosmetic change. I can live with it because I am able to fit the most important icons on the page. The ones in the Share box are good but more of a secondary nature in my view.
But I imagine that WP will soon be dazzling us again with improvments. One that I have suggested for the share buttons is as follows:
If you go to my blog and scroll over the share icons, you see a little message pop up. For the pre-set ones, the text is geared to the icon (e.g., "Click to share on Reddit"). For the ones I added myself, however, the text is generic ("Click to share"). It would be nice to be able to change the text. Not a big deal and no urgency to be sure, but something to think about.