The Old Ancestor of Hundred Flowers is not unwilling to break through, but he is a bit worried. He worries that once the decision to break through is made, the Eternal Sacred Land may arrange for their Hundred Flowers Holy Land to take the lead, and by then, they could easily become the cannon fodder.
Under the push of great forces, if the Eternal Sacred Land makes such arrangements, their Hundred Flowers Holy Land would find it difficult to refuse. Any refusal would easily earn them the reputation of disregarding the bigger picture.
In usual times, others might not target their Hundred Flowers Holy Land, but when it comes to breaking through, everyone wants others to be the cannon fodder, sparing themselves, which is only natural.
The Old Ancestor of Hundred Flowers worries about becoming cannon fodder.