If you want silly, have then FIGHT over what an element is called. People still get emotional over whether the 41st element is “Niobium” or “Columbium.”
It’s a good thing that a French scientist didn’t discover Einsteinium (atomic number 99), or it would have been named QuatreVingtDixNeufium. 
The IUPAC systematic naming convention stems from a recommendation from the Commission on Nomenclature of Inorganic Chemistry in 1978, under the chairmanship of Joseph Chatt. The recommendation can be read here:
J. Chatt, Pure and Applied Chemistry, Vol. 51, p. 381 (1979)
As for why this scheme and not another – Why not? You need something, and this is as good as anything, since the goal was to have the name directly related to the atomic number. Why bring hundreds and tens into the mix just to multiply up the number of name fragments one needs to deal with?
First of all, they’re a mix of Greek and Latin prefixes, given that we’re using -pent- and not -quinque-. Also, as noted, these are temporary names given out while we’re sorting out who gets to choose the name and whether we’ve actually confirmed that they exist. Once they figure that out, they’re given official, permanent proper names. That way, you haven’t used up a name on something you haven’t actually found. Wikipedia, as usual, has a good explanation of the system of and why the roots were chosen.
If you don’t like IUPAC’s naming system, you don’t have to use it. Unless you live in some totalitarian country where they flog you if you don’t use the element names specified in some local law, you can start a movement among your family and friends where you all call Element 115 “Aunt Sue’s Blue Elixir” and Element 116 “Rainbowdashium”. Having trouble getting people to go along? That’s life, and the IUPAC is having the same problem with you. If you succeed in starting a movement, good for you, maybe those jerks at the IUPAC will accept the new reality before they face obsolescence where nobody listens to them anymore because of how old-fashioned they have become. Language changes based on usage. People decide as a society what things are called. The IUPAC doesn’t seem to have any de jure power to imprison element-naming dissidents or ban publications that use “unauthorized” terminology. People respect IUPAC because they want to believe in some higher structure in life.
It’s just a placeholder name, dude. Don’t get your panties in a twist. Nobody’s gonna be bragging in 100 years about their Space Corvette’s bitchin’ new Ununpentium Drive.
Trivia note: The tiny village of Ytterby, Sweden inspired the naming of four elements discovered nearby: Yttrium, Erbium, Terbium, and Ytterbium. Not that the typical lay person has heard of any of them…
Frankly, regardless of the convention, I think the next element to be discovered should be called unobtanium.
