From what I recall reading, several of the generals expressed the opinion that the plan either needed to be executed immediately, or not at all. The plan was then delayed, and the Soviets kept building up forces in the area, leaving the German generals in question with a feeling of dread, like some impending disaster that they can't avoid. German intelligence was woefully inadequate at that stage (most of the fuel previously allocated to reconnaissance flights was being saved for other things), but what little info they did get was making the whole plan look like a bad idea. They had no authority to stop it, however, and the operation was launched despite glaring signs that the Soviets were expecting and prepared for it.
Other generals were of the opinion that waiting would gain nothing, so it was better to toss the dice and hope for a miracle, rather than wait for the Soviets to out-produce Germany and attack at a place and time of their own choosing.
Other generals were of the opinion that waiting would gain nothing, so it was better to toss the dice and hope for a miracle, rather than wait for the Soviets to out-produce Germany and attack at a place and time of their own choosing.