Whilst it's counter-productive to try to force users to upgrade their hardware it's possible to do so if new software works across the board but does more with new hardware. At the simplest level that could simply be by running faster - but software writers may find more possibilities than that.
As regards making use of older software that is no longer promoted it would be wrong to attempt to force all down the same path. Some, eg from magazine cover discs, may simply need to be identified, updated, and made available for download or on CD. Others may best be sold commercially by someone willing to continue to develop them. By all means try to 'rescue' software - but don't then leave it to wither because there's no one interested in keeping it up to date.