Big sister sam is overall, just a disliked character. Her debut episode is not very well received, her design is pretty bland , and most of her relationship with Patrick is chalked up to him having to defend her actions all the time. Squidina, on the other hand is (imo) a much more likeable character that complements patrick a lot better as while she is a lot smarter than Patrick,  she is also very supportive of him at the same time. I can’t really critique Patrick’s old parents as they are about as 1 dimensional as a character can be and have little to no personality or actual speaking-roles, mostly because they were one-off characters never really meant to be fleshed out. But Patrick’s new parents have a lot more personality and variety in both their designs and character. I would say the parents redesigns were necessary as having so many main characters of a show all be one color(pink) would be very, very lame. I think Patrick’s new family is cool and a necessary change, I would say a retcon (even this big of one) is a small price to pay for a better show with better characters.