True but i am pretty confident that once Letsencrypt is out publicly, clever folks will find a work around or post how to get LE to work with their relevant web host control panels’ server environments.
Then again it only takes 1 or 2 control panel folks to implement Letsencrypt to motivate other control panel developers to follow suit or be left behind. Then it only takes a few web hosts to offer up that control panel’s LE implementation as a value added service feature, then other web hosts might be motivated to do the same. Making money is one thing, but retaining your web hosting clients in the face of competition is another priority 
With that said with all 3rd party client implementations once of my concerns is defragmentation in that space similar to Android development from various phone manufacturers Preventing Letsencrypt 3rd party clients going the Android way?