Why has amplifier power become a big issue

What has changed?
People's perceptions of high end audio. The numbers, including pricing, have spiraled out of control since "back in the day".

If you are happy with your current amp and speakers, just ignore all of the noise. 

"Current" should be at the center of any power amp, IMO.
This becomes an important factor on current-hungry loudspeakers.

Your Vandy 2CE speakers are very nice indeed and can sound fine at 50W.
I do not know if they crave "current" or not?  Happy Listening!

I think, most buyers of today's high-end are not audiophiles and as such have different priorities. Having said that, other things being equal I prefer more powerful higher current amps, especially transistor amps. At the same volume with the same music you can feel the difference.

Nothing has changed except awareness that many speakers have not been driven to full potential over the years due to use with commercial gear like receivers and cheaper integrated amps without enough muscle to get the absolute most out of most modern speakers that tend to be smaller but retain low end extension meaning more current and beefier amps needed.     Usually the smaller and more extended a speaker the more the burden falls on the amp to make things click to the max.