Why do people like Kang Liang belong to the bourgeoisie?

Kang Liang didn't realize the backwardness of feudalism until he saw the progress of foreign developed countries, so he pushed Emperor Guangxu to launch the reform movement and prepared to learn from Britain and Japan to establish a constitutional monarchy. However, after the failure of the Reform Movement of 1898, Kang Youwei became a royalist, while Liang Qichao surpassed his master and further became a * * * faction. Although both of them are landlords, they both believe in capitalism. Although there are differences between constitutionalism and constitutionalism, they both belong to the bourgeoisie.