Your point seems inaccurate. In a mutual credit system you can set up a limit on how much money someone can issue. If the community set a common credit limit for everyone then all people are allowed to issue the same amount of money (in time-space). There is no one that can issue more money than the other, but someone may want to spend all his credit in a moment, and someone else in a decade. By setting the credit limit small you encourage people to work. By setting the credit limit high you encourage people to consume. The community could also vote to give more credit to the credible people, and less credit to the proved unreliable people . All this different and possible set up depends on what a community wants to accomplish, and it is related to governance. And of course this credit limit can be considered as some kind of universal dividend.
This cannot happen when a universal dividend is implemented by using a blockchain fiat currency and when everyone can issue as much money as the other one can. People in that case just sit down and receive the dividend. There is no incentive to work and procude wealth if you are sure that there will always be a mechanism that pays you, unless of course the dividend is small enough so that you are enforced that way to work in order to be able to live. How much big or small the dividend should be, this is also a governance question.
The above are also explained in a glance, at the article I provided to you.
But wait — Alice spent credits she didn’t have! True. That’s exactly how issuance in mutual credit works. Managing the currency supply in a mutual credit system is about managing credit limits — how far people can spend into a negative balance. Different systems set different rules about this, ranging from everyone having the same limit (e.g. 100 credits), to having NO limits and leaving the choice up to each person as to whether they want to extend more credit to someone deep in debt. It really depends on the community, the relationships, and the use case.