Slidingroof:
You should definitely care where the money comes from. This is because expenditure goes hand in hand with the revenue, and you would not want to spend above your means.
The houses you have shown us are great, but in long term the cost of maintaining those structures is higher than the one used to erect them. Therefore, you must have an economic model that not only builds but also provides sustenance in long terms. Ufisadi is not a tool for sustenance.
Ufisadi or corruption is something you should hate. This is because it has negative economic and moral effects in any countries. For example, you play by the rules and you spent more than ten years of hard work to build the house. Definitely, your action would spur economic growth, and also encourage others to work very hard because they see the fruit of your labour. However, if you neighbors built their houses using income from illegal activities, they would indeed undermine your moral standards. Nobody would value your hard work. As you can see today in Tanzania, those who do well are suspected of being fisadis. They are no longer role models.
In addition your neighbors will cause unnecessary inflation which indirectly will impact you and others who work hard and play by the rules. For example, today the values of properties in DSM have skyrockted. However, if you manage to decrease the level of corruption, the values would definitely drop and allow those who follow the rule of law to enjoy their labour. It's simple as that.