1. Updates
2. No privacy harmed
3. Not crammed with bloatware: choose what you want (fair)
4. Root access
5. Where are the advertisements?
6. Not willing to pay a company's 70% profitmargin for harming your privacy, cramming it with bloatware and adds.
7 (possible) android support through Alien Dalvik.

At the end, those issues are real. Google has proven it values a profitmargin of 70% on Android over their customers values (privacy, add-loading, bloatware).
If we can all agree on Google intentions, your question should be: why don't people prefer Sailfish over Android?