I get what you're saying (in fact, that's exactly what I'm going to do myself: wait for my 3GS contract to expire in the June-ish timeframe and port the number to a Verizon iPhone 5).
OTOH, for people who
need a phone now (and don't want an Android or Windows phone), this is a viable option. For some people, the AT&T network where they live/work/hangout is a giant failure. Obviously, they will be more motivated than you or I would be.
I gotta admit, the new WiFi hotspot feature alone has me intrigued. I almost bought a WiFi iPad from Verizon over Christmas just so I could get the MiFi 2200 hotspot deal with either the $35/3GB or $20/1GB monthly plans that goes with it (then sell the extra iPad, unopened, NIB). It'll be interesting to see how VZW prices out the 3G hotspot service in the next couple of weeks.