Maybe because they like Pruitt at 500K more than they like Crouse at 600K.
When the Jays missed on Bickford, they lost all of his slot dollars, so once again, it had no relevance on the signings of Brentz and Tellez. In fact, that case was actually a perfect comp to this one, because just like Maese, Hollon signed for well below what people assumed he'd sign for, and it freed up enough dollars to get the others.
Are you not reading what you're writing? So you're Justin Maese and you've got a pretty decent Texas Tech scholarship, you get drafted in the third round, the team that drafted you tells you they found something in your physical that makes them hesitate, and you almost immediately sign for half your perceived value, because "f*** it"? When you're hitting 96 and you've got a "pretty decent" commitment, if a team comes to you trying to low-ball you because of your physical, why would you immediately settle for half the slot?
The news that Maese was signing literally broke within a day of his draft selection. Sounds to me like the Jays talked to him before the draft like they talk to all the guys they're interested in, asked him if he'd sign for 300K if they made him a third rounder, and they got the go-ahead. Which would explain why there was no apparent pause for negotiations before Maese was going around telling people that he's signing. Rather than the idea that the team found something in his physical that very suddenly and very drastically altered his value, and yet, didn't result in any delay or hitch in the signing.