You are probably too politically disinterested to know, but Labour used to be run by leftists like Corbyn until Thatcher threw the entire country 10 miles rightward. Apparently people are now starting to realize the Labour party has morphed into a shitty Tory-lite party and want it to move back to its original ideals.
A quick search gave me this page, which lists pretty valid reasons why Mr. Unelectable got elected:
http://www.bbc.com/news/uk-politics-34126758
In general, neoliberal wankers should give up their notion of who is electable and who is not. You probably thought Sanders was unelectable even though he almost beat Clinton and did better in general election polls at the time than she. You probably thought Trump didn't stand a chance. Here's a scoop: just because you think a candidate is stupid, unreasonable, whatever, doesn't mean the general populace thinks a candidate is stupid or unreasonable. Thinking that some conspiracy must have led to Corbyn's election shows that you are probably living in an echo chamber and you are unable to confront the fact that a lot of people who think about politics come to different conclusions than you.
If you ever see me saying "thoroughly convinced by" in the context of most things then you can probably write it off as a trollpost--especially if it is in the context of politics and/or conspiracy. I'm not politically inclined--I'm not even going to pretend that I am--and am a bit of a sheep whilst also really disliking talking about politics for prolonged periods, but I'm smart enough to understand that conspiracies in politics (and, by extension, in most things) are almost always complete horseshit. If I make any "conspiracies" they are for personal entertainment only and never reflect my actual beliefs (i.e. no: I don't think it was just Corbyn bribing people).
As for your article, those explain why he was elected in 2015, but not in the re-election in 2016. I understand that Corbyn was elected largely on the £3 signup fee for labour. However, I also know that the sign-up price was put up for the re-election, and that a big part of why he was re-elected came from the re-election happening before there was an actually good candidate chosen to go up against him. It was Jeremy Corbyn vs. Owen Smith (a.k.a. that guy who nobody knows the name of) for Pete's sake. On the matter of Corbyn, before I even think about whether he is qualified for the job or not, I can tell he's the type of person that if I were to meet him and have a casual conversation with him irl then he'd be completely fucking intollerable, as evidenced by the fact that he said "I’m totally anti-sugar on health grounds, so eat very few biscuits, but if forced to accept one, it’s always a pleasure to have a shortbread" when asked what his favorite biscuit is. Like, seriously,
if forced to accept one? Jesus fucking Christ Jeremy, you could've worded that just very slightly differently and not come across as a
complete asshole. Not to mention he's a hypocrite, because he's stated that one of his hobbies is making jam--which raises red flags when you start saying you're "totally anti-sugar"--but I'm getting off-track. The biggest issue I have with him is that he doesn't really have a strong opinion on a lot of things, with his EU campaigning being very . He has a history of answering easy questions while dodging around answering hard ones (including in the very same meeting he had the biscuit question in), and in the only Labour leader debate that I was able to find the time to watch consisted of him giving the same vague answer in different words in response to every question--regardless of whether it actually applied to said question or not. He was voted in in the first place because of it only costing £3 to join the Labour party and vote on the leader, and after the re-election there has been a lot of backlash from a number of good voices in politics, such as David Blunkett who said "the re-election of Jeremy Corbyn as leader is a catastrophe", while various people in Labour and/or Labour Co-Operative--including the aforementioned David Blunkett, David Miliband and Ed Balls--have stated he is un-electable,
with Miliband writing a New Statesman article back in September which brings up the matter while going over other things. I'm not going to go on because, as I said before, I don't like talking about politics much (that and this thread isn't for discussing the ins and outs of whether Corbyn is competent or not), but yeah I had got going before I even realised and am not going to delete it after typing so much.