Because we are old and tend to stay with things that are familiar to us.
But why over cam an engine if it is less than optimum out come. Yeah it will work but why do that? As you say getting away with it. In almost every case in a street car smaller cam is better.
First statement was a joke. I should have included the word 'nostalgia'. So we are saying mostly the same thing. I do know that at least some of the younger crowd are or want to be a part of this though.
On a more serious note,
Running a 234 cam in a 355 isn't exactly over-cammed. Maybe in a 265, but not in a 355. There were guys around these parts that ran Isky 505's in 283-327's, and those cams were 254. There were some of them that ran pretty dang fast too, and they were street cars. You'd have to be a hotrod guy to understand I guess. I think the OP would, cuz it kinda sounds like he might be one. Having a smooth idle and no cam chop in 3rd gear while cruising town is a motor that hotrod guys in an old rod would want to kick to the curb! lol
The best plan is to pick out the cam, then build the motor around it, in a perfect world I would agree though.
Call Schneider cams in San Diego. Jerry Cantrell still runs the place, just as he has for decades now. You can talk to the boss, tell what you have, your motor, trans and rear gear combo, and most importantly, what it is you want to do with the car. From there, you get a professional recommendation. I started using them quite a few Years ago for my six motors and they have ground me some really terrific cams that broke in perfectly and performed exactly as described. A speck more money, worth it to me to get it right the first time out.
I blew the cobwebs of my Duntov Cam equipped Camaro, changed the oil, coolent, and built a 3.07 geared 12 bolt and went on the power tour and knocked down 15.5 mpg. Came home and left the 4.10 on the shelf and built a 3.42. Still sets off car alarms idling through a parking lot and I like it that way,