I have Harlequin Rasboras in a 10g tank right now. It is well filtered and they are healthy fish. BUT they swim very fast, and are a shoaling fish. I have 5. This is actually not adequate for this type of fish being is that they school larger in the wild. I know I am wrong, and I have taken the opinion of others, and currently have a 50g tank that I am setting up for the sole purpose of having large schools of fast fish.
My point is, I have very healthy fish. I cannot say for sure they they are happy. They don't smile, nor do they cry. I can tell you that mine are not as active as I have been told that they are. I feel this is because of inadequate swimming space. And 100s of people on this forum would probably concur.
Anyways, my point is, you are handing out poor advice. When I give advice, especially if I am unsure of its value, I ask someone to back me up, or correct me. I do not insult those that tell me that I am wrong in their opinion, nor did anyone insult you. A valid point was stated by someone that has way more experience than you. If I were you, I would take it as gold. I haven't lost fish due to errors since I started listening to the people on this forum. Maybe you should at least show some respect. Even if you don't listen to them. Do not insult them, because nobody did that to you.
P.S. Danios should be in a 4ft tank IMO, because they are fast darting fish that need a larger area to swim. They can clear a 4ft in less than 3 seconds. The longer the tank the better. It is the same concept as if you had a dog or cat. You wouldn't keep a Siberian Husky, a dog KNOWN to love running on a 10ft chain would you? If not, then why would you close up a fish that is KNOWN TO BE VERY FAST in a tank to short?