Jumppilot - Nonstop is exactly right, even if he was a little more verbally abusive than was probably warranted. Main point he made that is worth remembering: The first 10 years of your pilot career you're averaging about $20k a year, so why shouldn't your last 10 years be at $180k - it would make your average earnings for 1/4 to 2/3 of your career (20 out of 35 years) about $100,000.
Secondly, and more importantly to your question, you don't get what you're "worth" in this world, you get what you "negotiate". Those top-end 1% pilots making that wage are doing so because:
a.) The aircraft RASM -vs- CASM can support it (Revenue more than Cost). If it didn't, the company wouldn't have agreed to the rate as it would have put them out of business.
b.) The pilots believed their time, effort, knowledge, and skill were such that they warranted that wage.
c.) The pilots were able to negotiate that rate.
Personally, I don't believe making $180k would be "living like a king" either if you have 3 or 4 children with medical/dental bills (a lot of dental insurance doesn't even cover the basics and gets pretty d*mn pricey), tuition, and all the other fun kid expenses that go with them, a home mortgage on a house big enough for everyone, cars, a ski or pontoon boat, family vacations, not to mention taking a chunk out of your salary to make sure you have something to retire with because you're not going to be able to count on your pension. $8,000 a month (which is $180k less taxes and retirement investment deductions) doesn't go as far as you think, just ask one of those captains making that wage how much discretionary income is left after he or she takes care of all those bills.
Secondly, remember that statistically speaking, only 1/3 of airline pilots make it to age 60. 2/3 retire early because of medical, family, or other issues (like the DAL guys who are bailing as fast as they can so they don't take a half-million hit on their retirement with the new concessionary deal). Don't believe me? call ALPA and ask them for the stats... Far fewer pilots are making that top-end pay scale than you think.
Now 300k at the top end of the scale? I couldn't believe it when DAL and UAL inked those rates, and now we see them disappearing. Again, you get what you negotiate in this world, not what you "deserve" or what you are "worth". Hope this was in some way helpful for your understanding of why pay tops out at high rates.
p.s. I agree with the statement that this will hurt major airlines negotiating interests as well - Northwest has been negotiating with their pilots for SJ rates (70 and 90 seaters) and the negotiating probably just got a whole lot harder for the NW pilots with those rates on the table - can you say B Scale?