I meant that I think it is better to choose for an easy implementation, rather than a complex but flexible/compatible/reusable/... one.
What do you mean by 'ease of implementation'? For the moment I read that as 'problem complexity', the degree to which it is easy to implement a solution for a given problem. I could very well be misreading you of course.
If it is meant to be something like the complexity of a problem, I'm having a hard time comparing it to things like correctness because in that case, ease of implementation doesn't seem to be a quality factor at all.
If you are implementing a shipping system for your application, and you want to compute the shipping cost, do you want a 100% correct solution, or 90% correct? The 100% correct solution will check all shipping companies for every possible country, and compute the price. The 90% correct solution will only compute the shipping for countries like the US/england/etc. The shipping cost in other countries will be computed with weight_of_product * 6 or something. This isn't correct, but it is much easier, and can be done much faster.
Also, in some languages, 5/0 is infinity. That is not correct, but it is again easy to implement.
No, but if the code is easier to write, it is probably easier to read.
If something is easy to implement, it might be implemented fast, but fast implementations are no guarantee for readable code.
Something isn't just correct or incorrect, as with the shipping, it can be partially correct. You need at least n% correctness, of course.
I'd argue that that depends on what is in that 9% and the importance of it to the constituent and end users. Furthermore, whether you're offering 90% of a solution or 5%, it has to be correct or it isn't part of a solution to begin with. And if it isn't part of the solution...