when Yoda was thrown down because of absorbing all that lightning and the release of energy or whatever it was that made them go flying, it threw them both over the edge, literally; Yoda might have thought about the Jedi Order and considered his life and decided to leave, but if he wanted to keep or rebuild the Order, he would have continued and rebuilt it, before Luke. the Order was dead, and as long as Sidious was Emperor it would have been hard to start it again.
whats weird, how is it that only the Jedi of the coucil were shown dying, when there were probably hundreds more all over the galaxy? it only showed the council members, some of them, dying, not the rest of the council. and yeah, when anakin stormed the Jedi temple killing the younglings and padawans, this weakened the Jedi's practice even more, but did this have to destroy the entire Jedi Order?
anakin felt guilty by cutting maces' arm off and immediately Sidious came in with more deception, anakin eventually gave in and pledged himself. anakin was only thinking about himself and padme at the time and God knows what else, which might have been a stupid idea, but, it didnt change that he gave himself over the Sidious. Sidious took advantage of anakin because of how strong the force was with him; Sidious did this with (tried to do this with) Luke also when he realized who Luke was, the power in him, and the thought of the fall of the Jedi; and probably many more reasons.
could you imagine all the emotional conflict in anakin at the time? i mean people go through a lot when things take the toll on your emotions. and for whatever reason he let the dark side of the force consume him so much that it changed his entire ways of thinking. he listened to Sidious when he said:
"Do what must be done, Lord Vader. Do not hesitate. Show no mercy. Only then will you be strong enough with the dark side to save Padme." Darth Sidious
anakin did exactly what Sidious told him; did not hesitate, showed no mercy and became even closer to the dark side until his redemption; without saving padme.
could he of saved padme even if he knew she was alive or not? not if Sidious didnt teach him Plagueis' ability. do you think Sidious was really concerned with anakins love life when Sidious had his own plans for himself and the Empire? yeah, if he taught it to anakin it could have been used for many other reasons besides saving padme, Sidious would of left it up to him, but because padme was dead and anakin couldnt bring her back, and there is no mention of the power Plagueis suppossedly taught Sidious from anakin in the old trilogy, does this mean anakin or Sidious knew it?
"there is darkness in you Jedi Knight, i can feel it...."