I think yes for the issue of income it cannot be used as a benchmark, meaning when for example your income is quite large it does not mean you have to bet with a large amount too, in the end of course as you think that for this problem it comes back to the readiness of a gambler regarding how much they are ready to lose regardless of how big or small their weekly or monthly income is. On the other hand I usually measure it by percentage, meaning no matter how much my monthly income is I usually only allocate no more than 5% once a month.
Betting with a large amount will be too risky for us because we can not waste our money just to playing gambling. We must remember that we have many other things that need money so we can not use much money for playing gambling. Beside that, we don't have to conclude that we can earn money from gambling, When we almost lose much money in gambling, that will be a good time to stop gambling and leave it for some time. It is good if some people can allocate no more than 5% once a month because that is enough for them to use that amount to playing gambling.