I think that's a great point: it's difficult, near impossible, to make any particular piece of software contain 100% of the features that 100% of people want. Especially in the case of a tiny-minority feature, a specialized version that caters to your needs sometimes makes the most sense.

I just worry that people using some of these alternative browsers are opening themselves up to security issues since those code bases are less well-tested for security problems, and often they don't have the developer resources to implement things like process isolation and sandboxing.