Those days aren't gone, they are just different now. There are several kits for constructing brushless electric motors and lots of folks making their own from CD rom conversions. The average modeler isn't going to tool off any internal combuston motor that will produce as much power as a commercialy produced one unless he is a master machinest. Lamenting the change in R/C reminds me of some car enthusiasts who lament the death of the carb and the rise of fuel injection. Car enthusiasts today are extracting far more HP percentage wise than their predicessors ever did and instead of drilling out a carb jet they are tailoring a 128 bit 3 dimensional fuel map. Model aircraft are no different, the same sort of work is being done, just with the technology of the time.