One of the reasons why software is so bloated is because the developers are constantly using it on their high-end machines. When a customer complains that something is slow on their 7-year-old laptop, the developer often just shrugs and says 'works fine for me'.
I routinely run and test my new data management system on old, outdated hardware to insure that the speed is as acceptable as possible even when there are resource constraints. If a big database or file system query runs fast on old hardware, then when someone uses a high-end machine they will be truly amazed.