They removed a lot of the capabilities of Squeak and most of the nice legacy code included for educational and historical purposes, and neutered the object inspection tools. I understand that Pharo is no longer Squeak and the whole idea was to simply take Squeak and change not just the UI but the actual language. But I'm just a Squeak person.
actually, from pharo's perspective the goal was to remove bloat, things that didn't help active new development. as a result pharo images were smaller, and didn't have to support lots of old legacy code or objects.
another problem that squeak had was that it was built on top of old images, containing objects that date back to the beginning of squeaks history, and possibly even older than that, and because of that it was (at least at the time) not possible to verify the ownership and license of all the source that the image was made of. for some objects the source was even lost altogether. this made squeak incompatible with FOSS licenses and it was a reason why it was not included in linux distributions. which is one factor that limited its spread among developers.
one of pharo's goals was to remove those old objects and unverified source and make it possible to build new images purely from a verifiable source.
from a certain perspective, the inclusion of those old objects creates a certain sense of awe, considering who were the people that worked on smalltalk that created these objects, whereas pharo in that respect feels more sterile.
