In my opinion, this is mainly because the other Greasers who are Pony's friends actually mean something to him. By contrast, Randy is an enemy and Pony does not care what he thinks.
The other part of this is that Randy is so rich, being a Soc, that he just expects that Pony's house will be trashy compared to his -- Pony's house could never compare to his. But with the other Greasers their houses are just a bit nicer than Pony's so it feels more embarrassing to Pony to have them see his house.
Ponyboy Curtis was never particularly proud of the house he shared with his brothers in Susan E. Hinton's novel, The Outsiders. It was a bit run down and not in the best area of town, and he rarely (if ever) had any of his non-greaser school friends over to visit. However, the members of his gang were always welcome, and Ponyboy didn't seem to worry too much about what they thought. The Curtis's house was probably in better condition than many of the other boys' homes, particulary Johnny Cade's. The reason that he didn't care what Randy thought about the house was because Randy visited after Johnny and Dallas Winston had died, and Pony was still reeling from their deaths and his injuries in the rumble. At this point, Pony had little concern what any Socs thought about him.
he is griefing over dally and johnny's death . he probably doesnt care what randy thinks because what would randy do?he cant do anything