The FAA's stance on commercial operations long predates drones. I, as a non-commercial pilot, am prohibited from accepting compensation for flying people or cargo and the FAA has a very wide view of what constitutes "compensation". The theory is that if I am being paid, that might impact my decision-making process and change (for example) "it's too windy to fly today" to "I can probably land safely in this wind". To get a commercial pilot's license I would need to 1) accrue more flight hours 2) pass a harder written test and 3) pass a more strict practical (skills) test. More experience and training translates to better decision making and increased safety.
This rationale holds true for drone flights, with perhaps a decreased risk factor. A hobbyist might look at the weather and say "I don't want to fly in this wind, my expensive toy could end up in the neighbor's tree" when someone being paid could say "I have insurance". Multiply that by the number of expected drones in the next few years and it becomes a rather large problem.
Personally, I have no problem with the way the FAA is handling the situation. They're putting safety first, as they have always done
and being professional by putting a lot of thought into their new regulations rather than hastily pushing a poorly-written, loophole-ridden set of regs that need revision every 2 months. Imagine the confusion among drone pilots whether the new maximum altitude was 300' or 400' this month, and imagine the nightmare of writing, rewriting, and deploying new regulation-compliance software for the drones if the rules kept changing.