Diluted to Death

Imagine you own a Bugatti Veyron.

(For anyone reading who doesn't watch the BBC's Top Gear, if anyone is reading, the Veyron is a 1,000 horsepower luxury touring car, priced around $1.5M, one of the most expensive production vehicles ever made. So I consider it likely you, like I, have to imagine owning one.)

Now imagine that you take the Veyron to the garage for some work and, instead of a component made by Bugatti, your mechanic replaced the old part with one from a Ford Pinto. Depending on the part, there may not be a noticeable difference in performance.

But what if, every time the Veyron needs a part replaced, the mechanic slaps on some crappy piece from the Pinto.

Or for an example more of us can relate to, imagine you have a bottle of vodka in your liquor cabinet, and your lush uncle keeps drinking out of it, and adding water so you will never suspect.

Until you taste it, that is, and it becomes apparent just how weak and watered-down the vodka has become. If old unk does this often enough, the beverage will become so diluted, it cannot accurately and honestly be called "vodka" any longer.
"Vodka-infused water," maybe.

Likewise, swap out enough parts and the Veyron is no longer a luxury super car. It's a Pinto.

It seems to me that bands can be like that.

How many original members must a band lose before it's no longer honestly the same band people recognize? Which crucial members have to be lost to inferior replacements, or not replaced at all, before the performance is noticeably inferior and unsatisfactory?

How dishonest is it to bill your band as, I don't know, The Periodic Chart, when there no members of the beloved original incarnation remain?

You can call a Pinto, a Veyron, but that don't make it so.