Not a fallacy whatsoever. Given the choice I'd say that the apps on Android would be chosen at least 9 times out of 10 by a regular user. Pulse reader is better than any news app on WebOS, Doggcatcher better than any podcast app on WebOS, Android's Kindle app is better, Dolphin HD is heads and shoulders above Advanced Browser, there are a ton of calendar, grocery and scheduling apps that make the one's on WebOS seem archaic, WebOS best music player is only as good as the free one's on Android with nothing comparable to PowerAmp, Tango and Skype on Android function better than Skype on WebOS, where are the Flickr and Picasa apps on WebOS(there are paid ones but Picasa and Flickr didn't even do one for WebOS that would've been free), VLC can play all the formats that Kalemedia can and do it for free, and even the battery monitor and WIFI apps are much better.
They're better because to get attention amongst the myriad of apps on Android you have to create great apps. There's a good chance that an app developed for WebOS has no competition or very few.
The very best apps on WebOS wouldn't even be in any tech sites "top apps list" for each category if they were on Android. Obviously, some would be there that are the same on Android(Angry Birds and the lack of update Kindle app) and even many of the one's developed for both are more expensive on WebOS.
The OS is not the problem with WebOS, it's the quality and the lacking of many "must have" apps will always be the Achilles's heel(that and how slow the Touchpad ran before having to do all the tweaks). WebOS apps either are inferior and/or cost more than Android apps, or they just don't exist at all on this platform(Evernote, Netflix, Pandora, etc). The devs have made some great apps but you can find better or pay less by adding Android. If WebOS had the Android apps I'd never have even thought about installing CM7.