Your point is quite reasonable. Why did WADA and UCI target Santa heavily, and Froome is not as targeted? Why did all riders applaud Santa getting caught and don't say a word about Froome producing same power?
Totally valid.
I don't have a great explanation for you.
but I'll try:
Santa had a long career in Italian amateurs with good results in shorter stage races and one day events. He's been around for a while. A very coached and maximized talent. When this deviated from the well established mean, considerably, it raised eyebrows. Santa always had good days, he just never had good weeks.
Froome has less of a mean established.
Froome looks like a cat 2 on the bike, but he used to look like a cat 5. He's clearly not maximizing efficiency and hasn't been coached as such from a young age. But he's improving very fast, as he is finally addressing weak spots that wouldn't have been understood and isolated on a team like barloworld, as they would assume this would have occurred at a younger age.
He's always tested like a freak, but I think it was dismissed as anomalous, as he wasn't putting it into the road early on. remember, i tried to get him in 2011, i was just a few days too late, as I wasn't actually in Spain when the vuelta started and i didn't think so much would change in the first few days of vuelta (I was wrong!!!)
Also, he had big issues with parasites earlier in his career. Getting that under control changed him a lot. maybe they were like the spider that bit spiderman? kidding...
Anyhow, short answer is, i don't really know, but my gut says that it's ok and that he's real. But he's the only one who really knows.