Interesting pov 
I totally agree 200% that the star system is just dishonest and should be removed (for good old ones).
As for me, the explanation is different while far simpler (lol in math too).
Lets say there is a series 3/5
For lot of people, its superior to the average and worth giving a try or VERY VERY GOOD, when in fact some people want to click 2.5/5 because its totally boring/average but CANT bc there is no CUT STARS
Maybe its easier to "click stars" and "cooler" but for perfectionist people like me, its annoying that you can't more precisely give a vote, as in the mind a 16/20 and a 17/20 is a HUGE difference.
What if i want to vote 19/20, that its near perfect series, a crazy masterpiece with flaws (probably bc of small details OR author is bad for romance but worth ignoring)
Welp, now i'm stuck to choose between 4/5 or 5/5
That means in eyes of others its 16/20 good-but-not-a-masterpiece or 20/20 perfection series, which btw some people would find the review dishonest or biased (bc its a 5/5 shiny stars and that most voters indeed are biased for maximum voting).
Then the nail of annoyance of all annoyance of this system of stars.
What if the series is utterly garbage that you should dodge it ?
WELP.
THERE IS NO 0/5 voting function.
That means a utterly waste of time series, is a 1/5 hence 5/20 = a series bad in "meh-bad" lvl
A series having some "worth" to it. Like a first try series for a noob, when the truth is its a utterly nonsense series full of bs and nationalism and pure pain to read book.
And the big nuke to conclude everything, is that the final score is the average of all stars vote.
With a 5 stars system, your own vote have influence on the whole.
Give a 1/5 is nothing on spammed 5/5 compared to a 0/20