It's bloat. Memory use, startup time, attack surface, terms of use (although this is more with Pocket than Hello), number of things that need to be configured on install, etc.
I have no problem with Hello as a concept. I have every problem with it being part of the core browser as opposed to being an addon.
I have no problem with Hello as a concept. I have every problem with it being part of the core browser as opposed to being an addon.