A 1 hour turbo session leaves me unable to do anything other than fall off the bike.
I think turbo training probably needs a mental process/gear I don't have (can't stand running machines either)
CX races are the same as are hill intervals
CX races don't have traffic lights, traffic, gates, styles, walkers etc etc there's lots of stuff that gets in the way of you redlining for 60 straight minutes on a bike. Much easier/practical on foot. hill intervals are good (in a masochistic way), nearest good hill is 20min ride away so I've just added 40mins to my 60min hill training ride. YMMV, some lucky sods will have a gert big hill, with a nice trail/quiet road up it, right outside their back door, but I'm guessing most people on a tight timetable will find it easier to get out for a run than a ride. Plus any ride seems to involve a certain amount of faff to get out of the bloody door, 10mins for road, >15 for mtb, I have no idea why, it's more like 2 minutes for a run.
but like I said just I'm arguing semantics, winter and on holiday (both have have a bunch of other reasons besides time) are about the only time I run normally.