1/ The PIC10F222 requires absolutely no external components (internal oscillator & powerup).
==> The 555 DOES need a few external components (caps, resistors,...
2/ The PIC10F222 includes FLASH & RAM. Therefore it's operation can be changed by simply reprogramming the internal FLASH.
==> The 555 operation can only be altered by changing external components (desoldering/soldering)...
You can even use a cheaper microcontroller than PIC10F222 : PIC10F200 (6 pins SOT)
You have posted a problem, and also the solution for others.
I feel using a cheap timer IC (555) as one-shot, would be a cost-effective solution.