First, I've go to say that I never had the chance to fully test a Core m processor, but still from what I've read so far they good just for some browsing, mail, light VLC and nothing more but I may be wrong.
Then, having only a USB C port is a great concept, really and Apple as again confirmed it can still be visionary and ahead of time but it definitely is not something I would buy for that price.
Test one.
The Core M from last year is as fast as the MBA processors from 2011-2012. And those machines are still good for a lot more than basic browsing, email, and VLC. CPUs have been "quick enough" for a long time now for most people.
Yes the one port thing is a bit awkward today, but if you use bluetooth and wifi, you don't need ports very often. You can get away from USB memory sticks with something like dropbox or airdrop.
It's not an insurmountable problem, people will get over it.