RH charges $75 to transfer holdings to a different broker. If you have a big account that's probably worthwhile but I get the impression a lot of RH customers are small-time people who are just dabbling in the stock market for fun. If your account only holds $500-1000 of securities a $75 fee is pretty steep.
Or you know, just don't open any new positions there and transfer your funds back to your account once you have closed the rest like I did. Then you have nothing there, can deactivate your account and just open an account at another place.