Does GA flying in your own plane count toward a Airline Transport Pilot license? The video Why the World is Running Out of Pilots discusses a pilot shortage, and notes the tortuous path to an airline transport pilot license (specifically). It claims there are 1500 flight hours needed. 

I also know general aviation is in steep decline over the last 50 years, whilst the cost of GA aircraft have gone up dramatically.  I wonder if there is a connection between these two things. 

If you own a small plane and fly yourself around in the "Mighty Luscombe" for fun or Youtubing, do those flight hours count toward the aforementioned 1500 hours?

Is there a floor to the minimum quality of airplane which "counts" - do you need a Cessna class, or will a light sport aircraft, experimental, parasail, or a towed glider suffice? 

Does these 1500 hours differ in any way from the ~230 hours needed for a "commericial license", or can you do it all in the same Cessna? 

In a general sense, would it help the pilot shortage if the government would act to promote general aviation as a hobby, growing it back to where it was?
The video isn't very clear, but most of the numbers it gives are "total time". This is cumulative, so the 1500 hours required for an ATPL includes the 250 hours required to get a CPL, which itself includes the 35-40 hours required to get a PPL plus the 15 hours required to add an instrument rating to your PPL. Also included in there somewhere will be 10 hours to add a multi-engine rating.

All loggable time counts toward the total. It doesn't matter if the aircraft is an airplane, helicopter, gyrocopter,  glider, balloon, powered parachute, etc. However, at least in the US, ultralights cannot be logged because they are legally not "aircraft".

As noted in the video, most aspiring airline pilots get flying jobs as soon as they get their CPL, most commonly as Certificated Flight Instructors. Many schools even guarantee a job as a CFI for students who graduate. Few people can afford tonrent their way to an ATPL, and it just doesn't make sense to use loans to fly when there is a shortage of pilots to take jobs where they can get paid to fly instead.