We could only wish that buying some special material would make us go appreciably faster.
Well that depends what engine you put on it sir...
But the hit to my wallet wasn't as bad as it could have been, in general I'm a big fan of buying second-hand. Local bike shop gets to charge me for fixing the previous owner's lack of upkeep, I get a lot more bike than I'd otherwise get for the same money. Not to mention that new bikes are hard to come by these days.
Putting a motor on feels like cheating, getting a lighter bike is the easiest way to see improvements in your ride. Your weight and fitness levels are much more difficult to assess than changing to a different bike.
There's an argument to be made for purism, but where do you draw the line? Do click shifters ruin the purism of cycling? The presence of multiple gears? Freewheeling hubs? Are clips, straps or clipless pedals just crutches for people with bad technique? Does the presence of a chain and gearing decouple you from the raw and pure connection to the wheel?
Where does one draw the line?
Suppose we have cheap and light exoskeletons that people can wear and run for 100 km at 15 km/h on a single charge. Would that put an end to people running 5 km in 45 minutes with their own legs? I don't think so.
I might buy an ebike when I'm older (and I mean well past 60) but why should I use one when I can do 150 km in a day for fun? If I'm in hurry I drive my car.
Another use case for an ebike would be a long commute and I don't want to sweat on my way to work. It's not my case but I would consider a bike with a battery for that.
Still, if keeping fit was the ultimate goal, everyone would be riding heavy old steel frames instead of chasing sub-1% efficiency gains ;-)
There is a huge element of gear geekery involved and to an extent also some cargo culting. I know, I've been there myself for a bit. Now I ride a 3-speed stepover bike with a basket on the front, because trying to always go faster was going to get me maimed in traffic at some point.
I find the performance-chasing stressful, whether on a bike, in a car or in front of a PC, and we could all do with a bit less stress in our lives.
Still, for the vast majority of everyday cyclists, the "purity" of the experience doesn't matter, they want to get from A to B in a practical manner. They want to see things and do things, the bike ride is not a goal in itself.
For the sports cyclist with aspirations based on their professional idols, they want to ride what the professionals ride, not a simulation. Personally I think the whole concept of trying to ape the professionals is a bit silly, which is why I don't do it anymore :-)
Just calling it a weak motorcycle doesn't really explain anything other than the cyclist's confusion about what he wants.
When cycling a motor could certainly improve my power output. But as it's outside the rules of most cycling bodies' rules for competitions, I can't improve my times by putting a motor on my bike any more than I can lower the basketball basket to score more points.
Of course, that doesn't mean there's anything wrong with an e-bike - someone sprinting 70 meters is still running, even if they're not within the rules of the 100 meter sprint! And e-bikes are a fine option if you want to replace a car (for certain distances), haul a lot of weight on a cargo bike, as a general fitness activity, or to keep up with faster riders for social purposes.
Grill/barbecue backyard dads obsessing about charcoal vs. briquettes vs. gas, BTUs and so on.
Motorcyclists and their endless discussions about motor oil and chain lubrication.
Amateur DIYers with tool collections that be excessive even for hardcore professional craftsmen.
PC gamers with their obsession over performance tests of the latest CPUs and GPUs, mechanical keyboards and ultra-high CPI mouses.
In the end, it's all just a dick measuring contest. If you have fancier gear or you have fancier-looking graphs than your neighbor, you are better at your shared hobby, because the numbers say so.
At least the cyclists are finally realizing that super skinny ultra high-pressure tires are actually counterproductive, and that a wider tire with lower pressure performs better on the uneven surfaces of the real world. But because the super skinny rock hard tires performed best in tests on perfectly smooth rollers, everyone had convinced themselves for decades that more flexible tires were bad, because the numbers said so.
There is a different argument to be had if the point is "don't buy frames with road/tri geometry".
I guess my point is: some of us aren't just choosing shiniest shiny, we're choosing an option from the list that only includes shiny.
As you've alluded to ebikes exist already as do ICE motorbike; still we enjoy pedal cycling.
Just as the existence of cycling doesn't invalidate the enjoyment of running or skateboarding just because it's faster and it's the same for pedal cycling vs powered bikes.
The modes of transport are just different.