Who the hell said you that?
GNU/linux is a successor of UNIX, one of the first fully developed multitasking and multi user OS. So, does that mean it has to be like UNIX?
Are you totally like your grand grand grandfather? Yes, you have some features common but have many extra, don’t you?
Like you linux has also developed over time. It supports GUI and i think is more responsive than Windows. You like Windows or iOS because you are grown with it from childhood.but that does not mean GNU/linux is bad. Its only because you fear to try it. Yes i agree if you are looking for entertainment only, you may find windows is a level up .
If your budget for a new computer is really low, choose any linux based os , it will surpise you with smoothest performance possible at the least configuraions. Belive me or not, a pc with a configuration like 2GB ram and intel Pentium processor runs like a beast with Fedora 24 (a linux/GNU based OS by RED HAT).