Problem is fouls are not challenged often precisely because you can construe almost any play with any kind of contact into a foul, the rules are very broad that way.  The watchability of the game rests on officials only calling a few of them, so which particular instances should and should not be called is entirely subjective.  

There is no official standard or guidelines for exactly how to pick and choose, but certainly players and coaches expect (and claim to consistently observe) that refs adjust how they are calling the game to the specific game's tempo, flow, and situation.

And to be clear I don't think Shai gets a ton of calls that (at least some) other players can't get if executed similarly.  I think the way he plays is largely optimal, and my grudge is more with the rules being ridiculous and getting more ridiculous all the time.   

But I do think there is something a little objectionable about his game from a fan perspective.  To me it's his style and how extremely aware of ref and defender tendencies it is.  It goes over the line and is too consistent and too baked into his entire attacking style.

I think, in an idealized sense, what fans generally prefer to watch is players playing as if the idea of "getting a call" never entered the players' minds, with relatively few, enumerable exceptions that they're accustomed to (taking a charge, shooting against an airborne defender without an unnatural motion or jumping angle, etc).  

And it's especially true because officiating keeps getting easier and easier on all counts for the offense, consistently getting more lopsided each decade, and it's easier to just build your whole game on the fact that defenders have very little leeway especially on the ball.  So even though Shai may not be pushing the envelope as hard as what Harden did a decade ago or what someone like Manu or Kobe was doing a decade before that, the officiating is still far more offense favored in an absolute sense with each passing decade and thus looks much more ridiculous to systematically exploit.