Incase you haven't noticed. All changes to CM are done va "executive decision". There is only a small group of Core developers who can commit changes. So even the popular features are commited via "executive decision".
Comparing CMStats to Carrier IQ is like comparing a Ladybug to a Tiger in terms of danger. The big difference is transparency. The code is open. You can see exactly what is being sent and you can see when things have been modified or changed.
Not to mention that I am sure you are running GAPPS on your phone which is collecting a whole hell of a lot of information about you without any sort of OptOut.
If you get past the stigma and actually think and use the facts available to you this feature is doing a hell of a lot more good than harm. You do realize that you send more information visiting a web page from your phone, computer, etc than what CMstats is collecting, right?
In return the "information" is invaluable. CM is a very large and very successful project that cannot continue to sustain growth via organic addition. Careful thought needs to be put in for things like device support ("Which devices should be fully suported by CM?", "How many people are using CM9 and does it warrant supporting CM9 based Key Lime Pie for older deivces"). Language support "Does CM need a dedicated translator for Chinese or a team of translators to translate new feature faster and quicker".)
This information is not going to be sold, or used for advertisements (quite unlike your browsers User Agent string and the stats collected by Google Play or just about any website or popular Android app). It is used by CM to support CM. It's is very little to ask of the users who enjoy the features of CM completely without charge or any "hidden" costs (like advertising big data).