Their primary complaint is that the 1% have already used their money to gain political influence to advantage the further consolidation of existing wealth and to disadvantage those who would make new wealth, potentially at the expense of the existing 1%.
It has nothing to do with other consumption, or lack thereof, of the 1%.
We are not in this situation because some evil overlord made us do it, but we ended up here due to our collective needs and wants. And the way out is not by opposing an overlord that may turn out not as evil and definitively not as in control and we had imagined, but through the conscious modification of our needs and wants.
But all of that is an aside to my point, which is that you are still either mis-understanding or mis-representing the OWS position as something of a "blame everything on the 1%" philosophy.
OWS has a very narrow platform of "money has corrupted politics". The fact that OWS was roundly criticized as not having a point is attributable to the fact that the Occupiers didn't agree on much beyond the statement of the problem. That is: they all agreed that money needed to be taken out of politics, but they disagreed on whether, say, ethanol subsidies were necessarily bad, or GM seeds were causing problems in the developing world, etc.
Some of them obviously believed in those things. Others just wanted to see an end to 'too big to fail' and socialized losses. But those were not 'occupy's positions.
The shortage of resources that comes from overpopulation is a problem which needs to be solved in the long term. However it wouldn't be a problem just yet if it weren't for a handful of people hording the majority of the world's wealth. The problem at the moment isn't a lack of resources, but rising prices due to a shortage of resources. If income for middle and lower class families hadn't been stagnant for the past decades then those rising prices wouldn't have been a problem. That's what people are protesting. It's not a class warfare, it's not a hatred towards people who are well off (like myself). It's about needless suffering.
I better leave it at that.
Irrespective of whether they are the main part of the problem or not, I think that demonising them is a really stupid idea that just plays towards divide and conquer politics. Ideally they should be co-opted as much as possible, mainly because they currently have most of the money.
There are probably 1 billion people in the developed world enjoying a life of "consumerism, fossil-fuel burning and so on", plus a tiny minority composed of the elites of the global south. You may add roughly another billion people from the emerging economies (i.e. the BRIC countries), who have lesser, but rapidly growing, rates of per capita consumption.
We are already 1-2 billion people living what we'd consider a "normal life" by modern standards, maybe another 3-4 billion with tolerably low levels of resources, and 1 more billion in the most absolute poverty. Heck, I have not seen any study to confirm, but I suspect that the average pet in the US is better taken care off that the average child in a 3rd world shanty town (and probably have a longer expected lifespan too)!
So, yes, the population bomb is a problem, but it gets amplified by the per-capita expenditure, and the 80-96 percentile have a disproportionate weight on the overall effect.
(Contrary to OWS retoric, my opinion is that the "one percenters" are not the main part of the problem. They are not only too few, but subject to time and space limitations that prevent them to consume as much as their wealth would predict. At the end of day, they will use most of their money to make more money or gain political influence. What they use that influence for is yet another dimension of our predicament).