Agreed.I'd contend that the exact scaling of things like jumping is such a small detail in 4e that, while you could call it house ruling, its essentially just a matter of taste. Conceivably you might 'break' some sort of published adventure WRT a high Athletics character at paragon or whatever where the scaling starts to make jumping really remarkably better than RAW, but overall its not going to really bend the game, or create issues with other subsystems.
Adding to this:AD&D simply has no mechanical way to express the concept of "higher level PCs can make huge jumps and other athletic feats", though you can simply allow it, much like Pemerton is suggesting you can allow it in a 4e SC, though how to adjudicate any success/fail is of course left as an exercise for the GM in these 'classic' versions of D&D.
3.x certainly allows for variation in scaling, you could adjust the scaling of jumping easily enough, just like you could in 4e, but since there's a rule for all of 500 other activities that you might want to scale differently you could be doing a lot of work there, and these checks are sometimes worked into other subsystems, so there's somewhat more interdependency there that 4e's loose OOC task design doesn't generally have.
I think these basic system differences are something that a primer would want to address.
For instance, unlike in AD&D where, if the GM allows super-jumping there is no way of adjudicating the consequences, 4e has a way: there are the skill challenge rules, the level-appropriate damage expressions, etc. So a GM can easily allow an action declaration of "I jump to the moon" (or whatever), set a Hard (or Hard+5, or whatever) DC, and if the check is failed apply appropriate damage as the PC falls back to earth. The GM could even tax a healing surge (or something similar) as a cost of permitting the check. And, in the fiction, the GM could easily narrate the PC landing back on earth separated from his/her team-mates and have the party rejoining be a further complication in the skill challenge.
Whereas AD&D has no generic resources to tax as part of the cost of making the attempt, or failing it; and has nothing like a skill challenge framework for determining if and at what cost the party members rejoin one another.
3E likewise lacks these resources and adjudication frameworks, even if one went to the effort of rescaling in the way that you describe. And that means the issue is not just about degree of effort, but degree of game breakage. 3E is already fairly unstable around the amount of mathematical and build effort required to achieve comparable effects via different in-fiction pathways, and rescaling things would run the risk of just increasing that instability.
Whereas, in 4e, a healing surge is still a healing surge, a skill challenge failure still increase the failure count towards 3, etc.