I have an opinion about the boxscore, I think its purpous is to tell us what are that player best/worst skills, so we know what we want to train.
A guy with 35 mins got more stamina than a guy with 15, 5 TO's prob got bad pass/drible, 7 assists, good pen/pass, 0/5 3pt's bad jump range, 2 blocks and 2 steals, prob good defender...etc etc
The number of "balls" is relative to player salary, and so in my opinion does not directly means hes bad with only 2 balls.
A guy with all mediocre would have like 2k salary (probably your 2 balls guy lol) and a guy with all ridiculous and IS, ID and RB respectable would get like 3,7k salary (4 balls probably).
P.S - I love your quote: "2 balls only" Thats a normal guy!!! xD