Making it Patriots-centric doesn't change my opinion.
Sure ethics trumps money. But there is a gulf of difference between "Ill bump two Aderall and pull an all nighter so I can code out this new CRM" and say "hmmm, Ill undercut my co-worker by messing their work up so I look better".
I'll do whatever I need to do (within the confines of my actions not impacting someone else's rights) to support my family. I don't think I'm all the unique in that position.
And while this may be splitting hairs, I am not judging all players as guilty. I'm simply doing the following calculus:
1. Players are bigger than ever; genetics and modern nutrition only get you so far.
2. Players recover better than ever; yes modern medicine helps but that alone doesn't overcome human physiology
3. The NFL and NFLPA have some of the "player friendliest" drug testing thresholds in sports for PEDs
4. The nature of the sport requires bigger, stronger, faster more aggressive players to play what we all agree is an extremely violent sport. There would be way fewer fans, with way less money pouring into the NFL (and team and player) coffers if the game was played by flabby 36 year old dads like me schlepping around the field. Smaller, less fast, less powerful, less aggressive players are a detriment to the NFL no matter what they say about "PEDs and the integrity of the game".
5. The CBA laid out rules for testing are beyond player friendly; given drug metabolism rates, testing days, advance notification and the "player window" to show up for the test, these guys could take something on Saturday night, play a game on Sunday, take something post game for recovery, get the notification to appear for a test on Monday, take the test on Tuesday (24 hours to appear) and pass the tests easily. There isn't a sports governing body on the planet that has that "open" a drug testing policy.
All of those things (and more) form my personal opinion that it is naive to think anything more than a small fraction of athletes aren't doing something because their economic livelihoods depend on it (especially for the bottom 20 players on any given roster). I mean, if cyclists and Olympic athletes, who stand to make mere peanuts compared to what an MLB/NFL/NBA player pulls down, would do whatever it takes to win .....why would expect someone who has more on the line to be less inclined? Especially when we know there are people who already do meaning that the "average" is already enhanced.
An article, that while dated, lays out the finer details of my position much better than I can.
NFL drug testing policy called too mild
EDIT TO ADD - I forgot to address your last point. My assuming most players take something isn't saying they have no ethics.
1. I attach no ethical confines to "victimless crimes". Whatever "illegal substance" someone wants to put in their body is not a moral discussion to me.
2. Especially when the system in place to prevent cheating is as lax as it is in the NFL, allowing for "cheating" to basically be limited to those "dumb enough to do it right before a test".
If were talking about NFL players and say Track Drug Testing regulations, then it would be more of an ethical thing; say Ben Johnson doping versus a clean field who all played by the rules. When the rules are setup specifically to allow "some cheating, cuz the fans love the results, but not too much cheating" then the whole ethical argument is gone from the equation in my opinion. You're simply doing business how business is done.