Laschet had some pivotal key allies from deep within the party's establishment on his side. Notably the CDU's elder statesman no. 1, Wolfgang Schäuble, who had pushed heavily for Laschet both in media interviews and in the executive board's sessions during the past week. And I guess nobody dared to go against he old man's wishes.
Also, the whole situation had started to contain at least an implied threat: Either you make Laschet Chancellor-candidate or you can start looking for a new party chairman. That kind of thing usually works, unless they really wanted to get rid of their chairman three months after the start of his first term and five months before the next Bundestag election.
Implied question as to why this is the case though, these things don't happen in a vacuum, so there is clearly some reason as to why Laschet landed in the position he has, with the support he has. Like he oveperformed in NRW in 2017, in the leadership race - it happens often enough that I don't think we should necessarily run around with the perception that he is just completely crap that seems to have mostly been developed post-hoc in the placing him head to head with Söder
CDU < 27% with Laschet. >35% with Söder.
February 2017: "the electorate loves Martin Schulz".
(and ftr, I would be very happy for Laschet to turn out to be a crap candidate who hands the chancellorship over to the Greens
)
Might be a good idea to drop the german memes too / or at least translate them (admitting I've been guilty of the same in the past), as has been mentioned, most of the people reading this thread aren't going to be able to understand them.