Lockpoker hasn't existed in MANY years.... neither has UltimateBet (11yrs.?). CarbonPoker is also OLD and I've never even heard of the others.
But I could name off DOZENS of other pokersites that no longer exist today but you know out of all of those sites (& I have played on over 40 different sites) only ONE of them didn't fully pay out to me (but when I continued to play on the site I KNEW it was at a point where it was questionable because the payouts were getting slower and slower for all players. Debi actually helped a bunch of us get paid but then on my final WD I got ripped off for $1,100. It wasn't that upsetting for me because I had run that poker site account up from 1x $30 deposit & had a $1,700 cash I made from a ticket I'd won through a freeroll, lol (only reason why I continued to play on the site after it had become questionable).
OF the 'current' sites I play on today (8 of them), at the tables I play on, I am VERY confident I am not getting cheated... (and by this I mean via 'other players on the site'... not by the actual site themselve's)
Okay, for me it was just a few days ago that Pokerstars refunded me money because apparently other players were cheating against me among others.
But apart from that, your whole post shows that poker is not as safe as we would like it to be. And it doesn't matter if a few rooms closed or didn't pay out two, five or fifteen years ago.
The system we all live in hasn't changed. We're talking about billion-dollar industries in some cases. Insurance companies, banks, real estate, energy giants, automotive industry, sports, media, even states: Everywhere you can find black sheep who take advantage of people. Why should online poker, of all things, be the exception? Scandals are ubiquitous. When it comes to poker, I personally remember PKR and especially Full Tilt.
In the end, none of this is surprising. We know us human species gradually. Where so much money is involved, there will always be some who are willing to play dirty.