I like Nifi, but would be a lot easier for me to write code to achieve the same results from many of my experiances. Also ended up with the typical, how do get something that this doesn't have a plugin for to work ... ohh I need to go understand their plugin architecture and etc invest in a load of stuff which quite frankly isn't really of interest to me.

Its well worth using though because at the other end I've seen all sort of hand cranked code and maintenance for something that I know Nifi could achieve (however I only know that from using Nifi and learning where it doesn't fit).

Its the above pain which makes many people reticent to try out such tools.