I think GPL is a good idea (and ensures that everyone is having the freedom from a modified version of the code, and other things that it protects users from), but there is some problem too, such as I think it can be complicated to deal with.
For this reason, I had idea to make up a new license (although I will not write most of my ideas here but will do so elsewhere). But, its main working would be: mostly you can do whatever you want (including omitting attribution and copyright notices) without worrying about the license, but you cannot use legal processes (such as lawsuits, DMCA, etc) to prohibit these freedoms to any downstream recipients (regardless of how many). The license would also ensure patents can be used freely, disclaimer of warranty (if the license is included in the copy and the recipient has not paid for the copy), and some other things to ensure freedom (although there can be some restrictions on the use of trademarks (e.g. to avoid false advertising), and some things to avoid working around the freedoms in certain ways). You can be forgiven any number of times, though; the license will not be terminated. Furthermore, for a practical reason of license compatibility, relicensing by GPL3 and AGPL3 (and possibly also CC-BY-SA 4.0, for works other than computer programs) are also allowed, as long as you have a copy of the source code and can satisfy the terms of those licenses.
For this reason, I had idea to make up a new license (although I will not write most of my ideas here but will do so elsewhere). But, its main working would be: mostly you can do whatever you want (including omitting attribution and copyright notices) without worrying about the license, but you cannot use legal processes (such as lawsuits, DMCA, etc) to prohibit these freedoms to any downstream recipients (regardless of how many). The license would also ensure patents can be used freely, disclaimer of warranty (if the license is included in the copy and the recipient has not paid for the copy), and some other things to ensure freedom (although there can be some restrictions on the use of trademarks (e.g. to avoid false advertising), and some things to avoid working around the freedoms in certain ways). You can be forgiven any number of times, though; the license will not be terminated. Furthermore, for a practical reason of license compatibility, relicensing by GPL3 and AGPL3 (and possibly also CC-BY-SA 4.0, for works other than computer programs) are also allowed, as long as you have a copy of the source code and can satisfy the terms of those licenses.