the "before" condition illustrates what they improved - and what they made worse and probably why. they shifted the buffer to be between the cars and the bikes, rather than between the bikes and the pedestrians, but probably didn't want to make a bike lane with as much cross slope as the heavily cambered road already had. so by flatting out the bike lane and NOT raising the sidewalk they ended up with very small curbs. the curbs were already very small. making it totally flush would likely have resulted in standing water in the bike lane or buffer, and raising the sidewalk would direct water towards the entries of the buildings, which is of course not allowed nor good practice.
it sounds like the real problem is that pedestrians are now walking across it even more, and the even smaller curb is less visible. some tactile domes, yellow strip, or tightly space mountable bollards would probably all be relatively simple fixes. grinding the bike lane down to make it lower than the existing sidewalk would be expensive, messy, likely not compatible with drainage, and result in a pretty sloped bike lane unless the step was moved to between the bike lane and the road. bike lanes a few inches above roads are good, a few inches below, not so much. they're just gutters at that point.
