If you have to worry about "wearing out" a hardware port, you're buying junk hardware. I've got an old beater Toshiba laptop that I use for work, mainly because it's so darned rugged, that on average - I probably plug 20 different USB devices into it a day, and 95% of the time I always plug them into port 1, the same port over and over.. I've had the laptop for 6-7 years and the USB port shows no sign of "wearing out", and it's the more fragile and prone to wear 2.0 design vs. USB C. You aren't going to wear a USB C connector out unless you're plugging something into in and swinging the device in the air by the cord, lol. It's a very rugged design, USB C.
Simple fact is, much like the removal of optical drives in the Mac laptops, a vast amount of research has been done regarding what ports are actually USED. Why have things if 4% of your customer base says "we use them occasionally" and the rest of your customers say they don't use them at all?
In the end, were I in the market for a new MacBook with the C connector, Apple offers any adapters I might ever need for USB C.
http://store.apple.com/us/mac/mac-accessories/cablesMe, I couldn't live without an Ethernet port built in, but the vast majority of people are just fine with wifi and bluetooth.
I'll wait til rev 2 of the USB C equipped MacBook - that M CPU is just too anemic for me.
Like it or not, this is another Apple trend that will absolutely stick. Within a year, I expect virtually all mid range to high end laptops to be no different port wise than this MacBook - eg, 1 or 2 USB C connectors, and other connectors dropped outright.
Don't underestimate the value to people that simply don't NEED, or stronger yet - WANT - 10 different ports in stuff like this - having to pack around one single cable and a small power brick is a great attraction for people who live and travel with and on their laptops. John and Susie Hipster sitting at a Starbucks writing The Great American Novel on their overpriced Apple laptops generally would be overjoyed that the removal of ports makes the machine lighter, cleaner, smaller, and more importantly - gives better battery life. The less expansion logic/ports you have, the more room for battery cells you have, and Apple did some really neat things with battery on these machines too.
All this being said - I bet there are a lot of cranky high end users (Mac Pro, etc) that invested heavily in Thunderbolt add ons that are feeling awfully looked over right now.