Actually, in the current Demon Slayer Corps, although there are higher-ups who support and value Tanjirou, many more do not acknowledge him.
The reason is simple, because Tanjirou violated the rules of the Demon Slayer Corps.
As a Ghost Hunter of the Demon Slayer Corps, Tanjirou not only protected a demon—who was an enemy—but also kept this demon by his side at all times.
Indeed, the meticulously handled wooden box that Tanjirou carries with him actually contains a demon.
Therefore, Tanjirou faced hostility from many Pillars in the Demon Slayer Corps, with only the Water Pillar and the Insect Pillar somewhat taking his side and choosing to support him.
As the Flame Pillar, Kyoujurou Rengoku, because the head of the Demon Slayer Corps had approved of Tanjirou's relationship, did not show hostility towards him, but to say he had already approved of and chose to support Tanjirou would still be somewhat premature.