Lots of bad design choices here.1) Fonts are inconsistent. Some are huge, some are tiny. 2) Icons are far too big and waste your screen space3) No matching FireFox theme installed by default.4) Inconsistent colors (black taskbar, annoyingly bright icons everywhere else. Huh?)The Linux would needs to embrace functional minimalism. Trying to compete with Microsoft on who can make the tackiest default theme is not a good way to win over users.
Scientific research has shown that upwards of 90% of themes downloaded from the internet are ugly as fuck. Here's a couple classy GNOME themes that won't make you go blind or spontaneously vomit upon looking at your display.