I don't find the arguments about Opera == evil because it is not free software very convincing for a few reasons.
- You have alternatives were they to ever turn evil, so you're not supporting a monopoly
- It uses standard network protocols and toolkits/APIs
- It adheres closely to web standards (W3C recommendations and RFCs), any divergence thereof is regarded as a bug
- It does not try to hide its configuration or storage in obfuscated file formats, so I can choose to use any other browser tomorrow and export all my bookmarks and such easily
- It is cross-platform
- It is reasonably well performing
- It is well supported through newsgroups and a bug tracker
- Upgrade and student prices are reasonable
I mean, doesn't Opera satisfy everything that a proprietary software company should do (Quality, Price, Support, interoperability/no lock-in)? What more could they possibly offer besides open sourcing it?