Bitul Torah

batei kirkasaos "mevi liyidei bitul Torah"
-Why mevei? It should be considered bitul torah in and of itself?
Maharsha says that even though these types of entertainment have a purpose in that they "revive the depressed spirit in people" and also sometimes (with regard to certain theatrical productions) have constructive messages and inherent wisdom from which people can gain knowledge and education, they are still forbidden. Maharsha explains that actually because of these beneficial elements these entertainment venues are considered unhealthy for one striving to learn torah. Being that torah is m'sameach, the torah should be the tool to gain these benefits and any other outlet utilized to that end is "mevi liyidei bitul torah". According to the Maharsha the gmarah is telling us that any pastime used to replace the experience of studying Torah is considered "bitul torah".