In a word, tabs are portable, while spaces aren't (so tabs are not evil ;-)
I would say you are right, except for one thing. You will virtually always find situations where you can't indent properly with just tabs alone. Which means that if you work with tabs set at different size the code turns becomes very difficult to deal with. Spaces alone are much easier to work with. And they avoid the perenial argument about how long a tab will be. IMO forcing people to use your indentation is minimal issue, as the tendency seems to be that if you work on someone elses code, or on shared code, that you should follow the indentation style for the code itself, not your own preferences.