Of course, labour-saving is not the only reason a device may be brought forward. Many examples are about being able to do things previously not possible, regarding accuracy, repeatability and so on.
But the motivation to do things that were previously not possible is to provide labour-savings elsewhere. For example, a more accurate instrument might take longer to build but the increased accuracy could potentially result in significant efficiency improvements within other industries. The GP post is correct when one considers a global perspective.
Traditionally, industry would have to distribute resources to workers within an economy in order to generate additional resources, but this is no longer required. Industry is currently spending resources offshore leaving the domestic economy with insufficient labour. They make money but don't distribute it back (the trickle down effect). In the future, industry won't even have to do that as automated production lines will minimize the need for labour. So with industry not distributing the earnings, how do these resources get distributed?
You can see it now, the earnings of large corporations and those in charge are increasing at a much higher rate then that of a traditional worker. The trickle down effect is broken. What happens now is more of a "trickle up effect" - people spend money on goods and the wealthy syphon off a percent of each transaction. Their resources grow while everyone else suffers. The problem is that without a healthy middle class, innovation and productivity suffer. Even the wealthy will eventually suffer as a result of their own greed as a loss of productivity and decreased efficiency will leach away their wealth.
To prevent this from happening, those who hoard resources need to be taxed. The resources can be redistributed in exchange for various jobs being done - jobs that improve society and result in something of "value". Nobody likes taxes, but if things continue as they are then they will be required. When half the skilled trades are no longer needed, the status quo will result in some major problems.