If he is as terrible as you make him out to be, surely Lotto wouldn't be taking him back (with immediate effect might I add).
Never said he's terrible. He still has a lot of talent, and Lotto Dstny needs climbers. His mentality was fine in the beginning of his career, it was just the last year that was problematic. It's worth the gamble as they probably could get him on a discount. If he turns it around, starts looking at himself, and starts training like a pro (and as a climber), it could be a good transfer. Van de Wouwer isn't the type of guy that holds a grudge, he gives second chances, just like he did with Vandenabeele (who's struggling with Long Covid).
He's also really close friends with Van Gils who vouched for him.
Me being somewhat negative about Vanhoucke has nothing to do with what I take about DSM btw. I genuinly dislike that team, but I have also no empathy with riders who still choose to ride for them. They should know better, especially Belgians. Benoot, Van Wilder, Vandenabeele, Vanhoucke, how many examples do they need. And still we have young talents like Vlad Van Mechelen choosing them.