They may very well do so (which of course points to the weakness in the maintenance of line integrity) - and if the risk of death is worth it, well, that's a bargain they will have to live by. Clearly we are far, far too lenient on intrusions.
AoD
I think it needs to be pointed out that outside urban areas people frequently cross railway tracks or even walk along side them, and do so legally.
Several of the province's best known hiking trails are marked as crossing and/or following for a time, a railway corridor. This is essential in low-traffic areas w/foot paths or rural roads w/no sidewalks or signaled crossings.
It would make no sense for a farmer to have to drive off his/her land to get to another owned field on the other side of the track, nor for a hiker to have to diver 2 miles or more to the nearest road crossing.
Safety rules are clearly understood in most rural areas (not to say they are always followed).
In urban areas w/multiple tracks and high volumes of higher speed rail traffic, it simply doesn't work to allow informal use of the corridor by pedestrians, the risks are too high.
But in depriving people of the 'convenience' of a quick dash across the tracks, it is incumbent on the railway and/or municipality to provide a reasonable alternative, all the while making it difficult
to make the poor and illegal choice.
I wouldn't suggest there need to be crossings for pedestrians (or vehicles) ever 'x' meters. As obviously the demand for that and utility of that will vary by place.
Still, I think a good rule of thumb is that you shouldn't expect people to walk more than 500M out of their way to get to destination, and less is preferred.
So where there are clearly high demands for crossings that should be looked at proactively and funding made available where practical.