My last car was an '05 Tiburon GT, which I think is a beautiful yet woefully underpowered car. So, I got heavily into modding for a while. Catback exhaust, cold air intake, supercharger, intercooler (designed, prototyped, and refined by me...), strut braces, torque damper, larger injectors, Apexi NEO fuel tuner, brake upgrades, new taillights, HID headlights, new headunit, amp, subwoofer, car PC... The list (and the $$) can go on and on.
For me, the thrill was in taking a beautiful car and making it better. I added roughly 50% to the stock WHP, dyno tuned myself to ensure that my motor wouldn't self-destruct, and personalized it tastefully. My engine bay was a thing of beauty, and I turned every nut and bolt myself.
There are platforms that are designed for tuning. The Miata, Supra, EVO, etc. etc. etc. are great cars for people who enjoy it. The Boxster - not so much. I've done a few upgrades, but since everything I read indicates that forced induction + factory block = $10,000 hand grenade, why? The Boxster is a SWEET ride. With a few tweaks, it's magnificent.
I am in the process of finding my next project car - maybe an LT4 Corvette to supercharge. I LOVE modding. It's like carpentry, or electrical work - the satisfaction of finishing something and seeing your creation work is a feeling that some people enjoy immensely. Other people derive great pleasure from buying a piece of equipment and having it perform its task exactly as expected. I happen to enjoy BOTH. My Boxster is a wonderful machine. Do I enjoy making it my own? Yes. A couple of exhaust mods, debadging the rear deck, drilled rotors, and the flat black exhaust tips make it uniquely mine, but don't "rice it out."
While I certainly understand that you love your Boxster the way it came, I wouldn't necessarily look down my nose at those tuner guys. The good ones know as much or more about cars than any one of us will, and some of them have done some damn nice work building something spectacular, often out of someone else's crappy old used car.