Is PB insensitive to other people's feeling besides her own?

She has responsibilities, and, sometimes, in order to do that she needs to hurt the feels of somebody else, of simply be quite insensitive. Princess Bubblegum would not do something bad of hurt other the feelings of other people without a good reason (Ex: Making Finn and FP break up in Burning Low because she found out about the condition of FP).
In short: Princess Bubblegum is generally a nice person and does her responsibilities. But sometimes, she need to be insensitive to fulfill these responsibilities, for the good her and her people (that depends what kind of situation she is in).

Too much responsibility and focus too much on science will make u focus less on others's feelings as well.

The only reason PB is considered insensitive is simply since she doesn't pay attention to others and their emotions. Like all of CN shows, the genius cannot understand human emotions. It's a stereotype of a sort. They are called insensitive since they lack the ability to understand emotions. For example, PB directly stated in Earth and Water "...just want to see her reaction to the guy who broke her heart" when she was opening the door to the chamber with FP. She cannot comprehend how this would affect Finn.

She's not coldhearted, however. But yes, insensitive. Wouldn't anyone be like that when your studies and duties outweigh trivial matters such as love and emotion?
That's how PB thinks. The only exception to zei stereotype is Susan and Mary from Johnny Test.

(first off i don't want to have this one "deleted" -_- i believe that pbadventure didn't do it... so who ever else did it... DON'T...)

yes she is VERY insensitive... like i said... her "feelings" are very limited... i don't think she has the ability, as a full grown adult, to have any REAL connection with people... she hides behind "responsibilities" like it's some sort of emotional shield... and although she doesn't have time for "kid" things, she obviously has enough time to stalk FP in the woods and create the "perfect" sandwich... (i think jake's looked better X3) i mean, she obviously can't be Too popular, the only one who helps with her experiments is Cinnamon buns... and he screws up... a lot...

BUT, it is shown that as a KID she can have feelings and, well, not be a stick in the mud... she can even "like" someone as a kid... but as Finn and Braco have shown... she isn't a sensitive person...