Probably because if Cruz did it, he’d actually, you know, put up a real-looking misleading website with a bunch of lies on it. In fact, I bet Jeff Roe would put up a “donate to Jeb” page that actually sent the money to Cruz. The Cruz campaign has no moral compass whatsoever at this point.
Trump redirecting the domain that Bush was too stupid to renew is a pretty ruthless strategy, but it’s not lying at all.
Plus I’m sure Trump would be willing to sell it back to Jeb for a “fair” price. :D
Jeb can just have the domain back if it is owned by a U.S. entity. Case law supports relinquishing the domain.