I think tap-to-click is an abomination (on Windows, OSX and Linux). The worst was Windows when I re-imaged a laptop without the OEM drivers the generic Windows

I think tap-to-click is an abomination (on Windows, OSX and Linux). The worst was Windows when I re-imaged a laptop without the OEM drivers the generic Windows driver could no longer turn the feature off (argh!). But I think the attraction for designers is trying to support a pickup and drag gesture on the trackpad without using a toggle button.