Welcome to the forums and thanks for your questions, they are very well thought out.
Your summary of the pilot narrative is pretty spot on, but that really is the summary of any job. Nobody starts out at the top of their profession. The top surgeons in the world started out looking at sore throats and broken bones, with hard work and dedication they worked their way up. The top lawyers in the country were at some point a clerk in somebody else’s office. What those top surgeons, lawyers and pilots all have in common is that they worked hard and stayed dedicated to get to where they are now.
I will say that I have been an ALPA member my entire career and generally subscribe to their stances on matters that pertain to the profession. However, it is important to remember when reading a document from a pilot’s union that it is published with one very clear goal in mind, and that is to increase pilot salaries (which is a good thing). ALPA of course published the lowest salaries that they could find and were sure to leave out the signing bonuses that many of the airlines are now offering. I would redirect you to this site for a much more realistic picture of first year pilot salaries: http://pilotjobs.atpflightschool.com/2015/02/09/regional-airlines-are-offering-signing-and-retention-bonuses-to-pilots/ While no, those salaries will not make you rich, they are a lot better than what ALPA is presenting and are certainly livable wages.
As to the number of pilots with ATPs, that article assumes that every pilot wants to be an airline pilot, many do not. There are tens of thousands of corporate pilots (who mostly all hold ATPs) who have no desire to enter the airlines. Just Net Jets alone employs over 3,000 pilots,all of whom hold ATPs and very few of whom want to join the airlines. Then there are the thousands of pilots who simply fly for fun and acquired the ATP under the old rules when it was much easier to do so simply because they wanted to say that they had it. Again, these pilots have no desire to fly for the airlines. I think that ALPA is using some ver faulty math here to try and stretch to prove their point, it really falls flat when one looks at it objectively.
While we do talk about the pilot shortage here we do not do so as a promise of great things to come. The shortage means that you will be able to get a job sooner rather than later at a regional, but advancements to the majors were here long before the shortage and have always been the goal of most pilots. Adam and I both got hired on at the majors well before the shortage really started to affect the regional airlines.
Sure, when I was a new hire regional pilot things were tight financially, but I was able to buckle down, repay the debt and move on to better things. It just depends on what your standard of living is and how you chose to enjoy yourself. You must keep in mind that even at the new higher pay rates a job as a regional FO is very much an apprentice job, you simply cannot expect to enter it and make what the experienced pilots do. Any profession is like this, look at what doctors make when they are doing their residencies, being a regional FO is essentially like doing your residency. The pay does get better, but it takes a few years.
While I do enjoy flying that is not why I got into aviation. I saw that my father (a US Airways pilot) was able to provide us with a very comfortable standard of living while having a great deal of time off. I became interested in the job for those reasons and then later grew to like it. So far my decision has paid dividends, I have a great schedule and make a rather good living while doing it.
I actually like that seniority is what drives advancement in the airlines. Seniority is a great way tone absolutely fair, it completely circumvents favoritism and makes sure that everybody has the chance to advance in turn, not just when the boss decides that they like the individual. Pilots are not evaluated on their skills because we all have to be excellent pilots if we want to work at the airlines. The airlines do not hire mediocre pilots, we all pass the same check rides that hold us to exacting standards. That is how we can say that any flight will be safe, regardless of who is flying it.
All of these points aside, at some point you will have to look within yourself and see if this is something that you really want to do. I can make arguments for the career all day long, but at some point you are going to have to make that leap of faith and decide if this is something that you are willing to take a bit of a risk on. Remember though, that other than working an entry level clerk position for the rest of your life and career will require a bit of a leap of faith.
Please let me know what other questions you have or if I can clarify any of this further.