-- are the "architects and engineers" verified to be architects an engineers? or are they "Internet engineers" that would turn out not to be engineers if checked?
I know that as of 2012ish, AE911Truth made a decent effort to check those who sign the petition as architects or engineers, by calling or mailing them and asking for copies of their college diploma and/or licenses. I did submit an online signature once as an engineer back then, and after a few days got an email asking me to scan or photograph my diploma. I responded, truthfully, that I was merely testing their verification process, and their response was that no feelings were hurt. At no time was my signature listed on their site, they only show up after verification.
I had for a while made an effort to check at least the "Professional Engineers" - those who have a license from at least one US state to practice their branch of engineering there - and found that the vast majority (95% or so) were legit, were what they claimed to be. There were a handful of exceptions where someone had a license that a non-professional might confuse for being an engineering license, but perhaps had to do with patents or something. There were about three individually who were listed twice (with different profiles) - those were corrected a while I after I wrote them an email.
The only thing one could have an issue with is that they allow professionals who are retired or changed careers and are no longer licensed, or never practiced architecture or engineering after finishing a college degree (Bachelor's or better) in either. But they do apply objective criteria, and apply them consistently.
I have no reason to think things have changed fundamentally since then. They still have an active Verification Team that continues to validate A&E. The most current team leader was (I assume still is) Xander Arena. Here is an interview with him on AE's own web radio show:
Source: https://soundcloud.com/user-989685163/verifications-team-leader-xander-arena
-- comparing a petition from this group that formed around a multi-year effort to a petition from the general public that may have only ran publicity for a few weeks/months is apples to oranges.
Indeed. The petition is more than 13 years old. They never followed up on whether signatories changed their minds in the intervening years - or died.
And 13 years is a very long time: The petition has been online for 4875 days (or a bit more). In that time, they averaged under 0.7 signatures per day from architects and engineers. In all these years, there was only one (2009/10) where they had more than 1 signature per day. So this has never really gone viral, it has never interested the professional communities. Gage has been toiling tirelessly to pick up the converts one by one.
-- to support an organization, you don't have to convince everyone; you just need to find the people who are convincible. Compare to email scammers: their mails are unconvincing to most of us, but those who respond to them are the kind of suckers who might be made to give their money to the scammer. While I don't know that AE911 is trying to scam anyone, like all conspiracy theorists, they certainly would profit from having the support of people for whom critical thinking is hard and who enjoy seeing themselves as opposition to authority. The "meme"-type graphics work well to that end.
The prevalence of some mental disorders is higher than the percentage of licensed engineers who signed up. Of you can find fools among supposedly well-qualified professionals. You find physicians who believe in this or that quackery. You find biologists who deny speciation by evolution. I once talked to an American graduate student with a BA in political sciences who swore that he voted for President/Vice President directly and denied that his vote actually went towards a slate of electors in the Electoral Collage.