Power comes from the # of dollars, not the margins.
It isn't the profit margin that gets people riled up about the oil company profits, its the number of dollars. You know that. The large bank account balances give them the power (whether they use it at the moment (or ever) or not) to: buy up competitors; buy up promising technology and sit on it; buy up mineral leases that competitors might use to bring products to market faster than they might choose to do; buy up advertising to sway public opinion; contribute to political organizations, parties, and candidates' favorite causes; etc., etc.
MS got to be powerful because it had a large bank account, not because they had (say) a 60% profit margin. It's not the margins that matter. If XOM is making huge profits because they're a huge company, well maybe they shouldn't be quite so big. They were split up once already, for very good reasons....
Comparing ExxonMobil's profits to some company that has a much higher margin misses the point.
/soapbox.
Cheers,
Scott.