That's fair enough, and it'd be great to see "proper" paths and direction markers like you'll see on the continent. But these paths must be planned by competent authorities and agreed with whoever is the appropriate interested parties. It's not the job of one man with a spraycan.
BTW I've come across some bits of tape and one orange jacket hanging on a pole (possibly as markers for the Art O'Neill walk considering where they are located) still on the mountains.
I've often enough come across bits of tat like that when out & about on the hills. In some cases I've suspected the hill running community who have marked routes with wee wands and tape and then neglected to remove them all afterwards. But I think that's improved? Orienteers can also be at fault in the forest environment as it's common practice to mark control sites with ribbons etc., prior to larger events, tat again that's not always fully removed afterwards, when everyone is rushing to pack up after an event.
But on subject of self reliance, I still think the mobile phone is the biggest change in recent years. When I started hillwalking, we just headed off for long treks across the hills, leaving a vague note behind. You learnt to navigate, route find and look after yourself or else you came unstuck, missed the bus and suffered a long painful walk to extricate yourself. Nowadays my kids can't move without their phones and can call at the drop of a hat. Yes, it's nice for reassurance and some peace of mind but at a loss of some self reliance. And I carry a phone myself now when out on the hills, but hopefully not to use.
The phone really is a bit of a mixed blessing and one suspects that there are people who would not venture up some places, if they didn't have that potential back up in their pocket. Often heard it said in places like Fort William in winter, where there are good MRT's, that climbers (and walkers) will take on more ambitious routes that prudence might dictate otherwise. On the basis that they can always call for help.. So, a bit a loop going in situations like that. If you have good MRT, people will invariably use the service!
There's a designated volunteer that goes around after each hill running race organised by IMRA to demarcate the course, and they just use ribbons.
Around Crone at the moment there's currently a lot of similar tape but Coilte have put that down as they're harvesting around there at the moment.
I used to do a bit of hill running, when the knees were in better condition, so I'd have an idea of some of the routes used and markings. It's easy enough for someone to miss picking up a bit here & there, particularly in poor weather. No big deal - if it's obviously old, I just pick it up and stick it in the bag. There's much worse in terms of hill litter left behind..