I think you're looking at the odds shift in absolute value terms, when you should be looking at it in terms of percentages. The shift from +250 to even is qualitatively different than the shift from +750 to +500 because you can make big profits on a very low stake bet with either of those dog odds. But when something goes from +250 to even, you have to move up to your unit bet in order to make a normal profit, and the loss actually stings...I think that when a fight goes from +750 to +500, it's lost 33% of its line value (250/750). And when a fight goes from +250 to even, it's lost 60% of its line value (150/250).
No, I get what you are saying and I am with you. I shouldn't have said technically, instead I should have said "it feels like." I just feel sometimes like it is giving in to the book when odds change that much and I am just settling.