Obi-Wan had never thought of his Coruscant apartments as luxurious. He took a vow of poverty when he became Qui-Gon's padawan, and was happy to do so.
He supposed he should have guessed, from Anakin's initial shock, that the Order's standard of poverty and Tatooine's were not quite the same. It was one thing to live quietly in spare, colourless rooms, possessing nothing but a few sparse furnishings. He was a Jedi Knight and victorious general; the Order and the Senate had naturally provided him with both the necessities and small comforts of life, and would have been glad to do more.
He never asked for more; he was a Jedi, called to the ascetic life. But compared to the living he now eked out of the desert, that life was positively decadent.