I think the design is innovative. Sometimes you just need 10mA @ 5VDC derived from the mains. How do you do it ? Do you get a Mains to 9VAC transformer & then implement the normal PSU design OR do you design/purchase a Mains to 5VDC converter. These options are expensive and bulky for just 10 mA @ 5VDC. So something cheap like this design is just the right thing perhaps. Might be inefficient but thats OK you are not using much power. This design does not generate noise (like a DC/DC converter) which is beneficial if you are powering some analog circuit with includes opamps, ADC's etc.  Off course the open 220VAC nets are dangerous. Cover them with something & make it safe !

What's that, a suicide machine?

Very bad design.

You really ought to warn people that this is connected directly to the mains and can be DANGEROUS. A decent SMPS is safe, can provide far more power, and doesn't cost much. You can probably get free ones from recycling bins when people are throw out tablet and external hard drive power supplies.