Here are a few things off the top:

- horrible optimization

    - video calls will easily bloat 1-3gb of ram

    - e.g. sometimes you click to write... you get a spinner, wait 10 seconds

- yeah, all things in one interface

These are opinions. People can have different. To me, its just a slow and difficult to navigate mess that doesn't know what it wants to be.

It does know: it wants to be everything -- they remind you in every ad!