My view of it is that there aren't that many basic concepts to discover in the back of your garage. Particle accelerators, high-field NMR machines, electron or AFM microscopes, huge ground-based or orbital telescopes are needed to make the next discoveries in their respective fields because the easy stuff, that could be seen with bubble chambers, low-field magnets, optical microscopes and small telescopes was already discovered. It's a matter of diminishing returns.
Scientists have been doing their jobs for hundreds of years, no one is going to discover an improved version of the laws of gravitation with a 100 dollar telescope. What may come out of observing dark matter was obtained with multi-million dollar equipment, collaborative effort and brilliant minds going over and over the same thing.
Granted, there may be things to discover that can still be attained in a garage. In hindsight everything is easy, but if no one is looking, there may still be amazing things still to observe in your kitchen lab. But expecting the cure for problems of the world to come out of a bunch of semi-amateur scientists is betting on the wrong horse... it may happen in a field or two, but it won't be the future of science.