There is a lot of truth to this, however, you'll notice on the gun that fits you perfect, your shooting 24 or 25 on the first round with the new gun. A friend who is older but of similar build to me, handed me his skeet gun the other day and I shot a 25 first time with it. He had work done on the length of pull from the stock length. Seemed to make a difference. If you want to shoot better off the bat get a gun that fits.
Anyone can adapt to a new gun, but the why would you want to have to adapt if you can just pull it up and bust clays.
As far as blowing smoke up a wildcat's ass......money spent on a target gun of a decent manufacture you will have that gun a lifetime and then still be able to hand it down. Buy a cheaper gun (Turkish over and under or something) and you'll be lucky if it survives 2 years. Now that said you can get a decent target gun used for less than $700, but if you want something new, that's tough to do.
The trap diva's will always have their fancy guns where they blow money on, just like the Harley diva's who spend a ton and then cake decorate and will never get their money back. Monster truck guys who lift their truck up and spend thousands and never drive it thru mud. Pick a sport, Golf, Archery, whatever, there's always people who buy top end, but don't need top end for performance because even with the new stuff their scores don't improve.
In the end, most guys that can shoot worth a crap can pick up most any gun and shoot a 20 with it....even sub gauges. But I'd rather have the gun I pick up and score highest with off the bat. And once I knew I'd stick with it, I wanted a decent gun I could shoot a lot, that will last, because the more you shoot one gun, the better.