Why are mini dv cameras used to film skateboarding?

Question

cameras like sony vx1000, vx2000, canon gl2, ect.

Answer 1

Because they provide the best available video quality. The three cameras you listed are standard definition cameras that have pro-grade features including the ability to add a lens (like a fisheye) easily.

Use of a miniDV tape based camcorder also provides for "automatic" archiving (there is no extra video archive step like  hard drive and flash-memory storage requires. At ~$3 per hour of video (that is how much fits on 60 minute MiniDV tapes - and that work out to about 14 gig of hard drive space for standard definition or 4x that for high definition), it is the least expensive storage media available. MiniDV tape has a good, long, shelf life; the three cameras you listed have external mic jacks and full manual audio control... full easy-to-get-to manual focus and iris/exposure controls... and have better low-light handling than most consumer camcorders.

The ONLY mid-range pro camcorder that uses flash memory is the Panasonic HVX200 - P2 cards. The ONLY hard drive camcorder in the pro-range is actually any miniDV tape based camcorder with a FireStore (or similar external drive. Both save to DV or HDV. NOT highly compressed MPEG2 or AVCHD.