I a lot of cases I agree with you. This, however, is not one of those cases. I'm not saying you are wrong and you can certainly do as you please with your own machines. It would be interesting to see what you can do with an upgraded TRS-80.
I generally tend to keep my computers stock, especially if I only have one of them. The 128k Mac, to me, gets it's value from being 100% stock. I have a 512ke. I don't need another one. Typically I don't consider RAM upgrades to be a "stock" modification, but I do in the case of the 128k. To me it even decreases it's value if it says "128k" on the back of the case. Those 128k's, of course, were the ones sold after the 512k was released. The 128k's that only say "Macintosh" are truly the first Mac's.
Again, these are just my own personal opinions. Collecting Mac's just happens to be a hobby of mine.