...the only motivation that you could possibly have for this is to try to use desperate emotional pleas to cheat your way into some benefit...
But as I mentioned before, we don't *know* all the circumstances, and really can't assume he's just trying to get some benefit.
In the example given, the only mechanical benefit I can imagine is trying to skirt around treating it like a ranged attack in order to prevent an Opportunity Attack from using a ranged attack in melee range, however if he isn't doing that then I can't imagine what other benefit there would be.
Unless he was trying to set a precedence with this rule in order to exploit another power in the exact same way.
Without actually being involved, the rest of us don't know if it is an attempt at abuse, or merely just not wanting to bother with mechanics that really are insignificant to the outcome (as in the example given). We also don't know if the DM is being unnecessarily inflexible as well. We can assume and point fingers, but only those at the table really know the whole story.
Sometimes there are problem players, sometimes there are problem DMs, and sometimes both of them just meet in the middle.
I have played with players like you describe Draco, and I know they exist. I've also played with inflexible DMs that just wouldn't cut anyone a break for the sake of fun or roleplay, and would even arbitrarily interpret rules against you, when the rules fully support you.
Example, one of my last DMs forbid me from taking 10 on a Performance check with my bard in order to do a routine street performance that I decided to do just to pass the time. The reason was because the DM fancied himself to be a performer of sorts (a poor one, I will say), and believed that there was no such thing as "routine" when it came to *performance*, and there was always a chance something could go very wrong.
When I had a character concept that just didn't work very well with 3.5 D&D classes. The closest I could come was a bard. I explained my concept and I asked him if I could trade 1 class skill (that was useful, but didn't fit my character concept that I wanted) for another class skill that suited my concept. He flat out refused, and only would allow me to trade out one of the key skills that was necessary for my concept for the other skill (that wasn't even a powerful skill, just fit my character).
With the same character I asked if he would allow me to forfeit evocation and conjuration spells in order to pick up divination spells, and again he refused...
Anyway, back to the point, we don't know the full story, and we really shouldn't jump to conclusions without knowing the whole story.