Because if he will lose on this one, I don't know what career he needs to build with.
This is maybe why they arranged the fight in his home country, maybe to motivate him to win on this fight once and for all.
There's no way Inoue will face him this year, Casimero has a lot to prove before he will face Inoue on the same division.
I agree, he needs to do his best in every match he got. At this stage he needs to prove himself and make himself popular and in-demand for the fans to take the interest of other ranked boxer. Casimero needs to make himself worth fighting even though he do not have any belt and getting popular is one of the way to make these boxers on upper rank and even the sanctioning bodies to take notice of him and give him a chance to rank up or even a title fight in the future.
True, if Casimero failed to finish his opponent or won the fight, the hype he is building in the previous months in his current weight division will poof. And more probably many will not take him seriously and will ignore his camp's fight request because it isn't beneficial for their boxer's career climbing.