Clerk, you found a list from Wikipedia which doesn't explain anything.
I want to give you some info about some of the athletes in the list.
LYDIA CHEROMEI : was banned for a pharmac against sterility, because she didn't inform IAAF about the assumption. This doping was so equivalent a "cheat" for enhancing her performances that, 7 months later, she had the baby. In this case, AK was guilty because didn't support the appel of Lydia, who asked to cancel the sanction, giving all the evidences about the reason of her therapy (so, not doping), when she came back running, two years later.
MOSES KURGAT : he was banned because positive to a medicine he took directly in Korea, two days before his Marathon (he was 3rd in 2:08:40). He had very strong cough, went to a local pharmacy with the translator, didn't understand the local Language (and the phramacist was not informed by the translator he was an athlete), and took the pharmac they gave him. After the race, during the antidoping procedure, he showed the package of the medicine bought 2 days before the race. IAAF accepted the "bona fide", looking at the evidence, and the first ban was for one year only. After this, AK enhanced to 2 years the period of ban, for showing they fight doping......... and of course responsibles were foreigners agents !
RONALD RUTTO : He took EPO before winning Linz Marathon in 2:11 (so, two minutes slower than his PB). He was cheated by a pharmacist in Iten (who usually went to drink with him every night, till when they were drunk...) who told him to get a medicine for increasing his recovery.
The pharmacist was the owner of the pharmacy "Glory", and myself informed AK about the situation, but nothing happened....
MUSA AMER : he is another case of big stupidity, but not of cheating.
I was the head coach of Qatar when the fact happened. Musa Amer was not in training with me, but with another Moroccan coach (called Driss). They went to train in Ifran, and he had a stress fracture. He couldn't train for 8 weeks. During that period, he took some steroid because one local doctor told him could help the process of recovering from the fracture.
He never supposed antidoping could go there for testing an athletes not competing, but the pool of doctors arrived Ifran for testing all the best Moroccan athletes, and, finding him (4th in OG in Athens), they tested him too. As Qatar Federation, we documented to IAAF his situation, giving the MRI and scintigraphy of two weeks before the antidoping test, and again the MRI and scintigraphy of 3 weeks after the antidoping test (he was still injured), showing he could not train during all that long period.
The answer of IAAF was : "we well understand his goal was not to use steroids for enhancing his performances. But he did a mistake : rules are rules, and he must be banned two years because was stupid".
RAEL KIYARA : I don't know well what happened. But I know that, two years before her positive test, she was with the management of Gianni Demadonna, and I had the opportunity to follow the training of her Group (the coach for Gianni is my follower Gabriele Nicola,also coach of Mary Keitany). She was very worry about her health, because had a diagnosis of a cancer in her breast. She stopped running for more than one year, and took medicine for that reason. One and half year later, with another manager, she ran under 2:24, but really I don't know if she took some PED or was positive for the medicines she had to get for her old problem.
A list doesn't give the full picture of the situation. If is true there are doped athletes that are not caught by antidoping, it's also true there are "officially doped" athletes who are completely innocent under moral point of view, but did some mistake, for ignorance of the rules.
That's the reason because, in spite of the number of doped Kenyan athletes, absolutely it's wrong to speak about "widespread doping" in Kenya. But it's obvious AK needs to start a more strong educational campaign, because the cultural level of the most part of runners of middle level in the Country (who could be of top level in every other Country) is not very high, and can be easy to cheat them, if there are doctors, pharmacists and some manager looking at personal advantages only, without moral values.