[ryandvm]

Because half the Flash "enabled" pages I load on my Android phone end up crashed, lagging, or completely borking the touch controls. About the only thing Flash ever works for on my phone are simple ads or video players (with unresponsive playback controls).

That said, not wanting to use something is certainly a fine reason to not want it installed. For example, I don't want to use closed media formats. I also don't want others to use closed media formats because I believe it to be detrimental to long term archival and sharing.