The spokesmen of protesters are demanding the extradition law to be upheaved indefinitely and Carrie Lam to be dismissed, one of which has happened already. Four months back there was absolutely no traction for any massive protest like this, not to mention the flares of violence. Even though this law has been in the making for years and published in March of this year. Can you think of any other legitimate reason the overall population is demonstrating so fervently other than dissatisfaction about the way their current government is running their city into the ground?
You speak of moving onto the mainland as a solution to purchasing power but I don't think you have any idea what it means to uproot your existence in a city which you consider your home. Especially when you're living from paycheck to paycheck and can barely afford the housing anymore. It's not as stupid to the majority of the inhabitants working in the service sector in Hong Kong and the fact that you see this as an 'accusation' to protest instead of a right to demonstrate is quite telling.