There is no "correct" way to collect bikes. It is just all good.
Some folks prefer a particular brand (Schwinn to Masi, it doesn't matter) perhaps due to having one (or wanting one) years ago. Some folks gravitate to a particular time period, perhaps because they got into bikes then. Others may be drawn to particular team or racer bikes, perhaps because they saw them at a race or just liked them for whatever reason.
I have acquired some Colnagos because waaaay back when, that was the first really nice bike I bought. There are other great brands, I just am drawn to the Colnagos. After I attended the '90 Tour I wanted a LeMond-raced bike. I finally found one some years later. I rode it for a bit and it hangs across from my desk in my office. It reminds me of the Tour, his win, and some very special moments for me every time I look at it. I scooped up an Armstrong-raced Motorola Merckx recently when I found it and did a resto. I just like it.
I acquired all of my bikes just because I wanted to and not for any appreciation or value issues. Like I said, it is all good and none of it is right or wrong.
Walter Nash
Tucson, Baja AZ