>I found it to be especially true with testing. I've lost the count of how many times I heard "we didn't had time to write (more) tests". But testing is hard. And when given enough time, these developers don't magically start doing it "right" overnight.

Bingo. It's not necessarily only skills though. It can be myriad reasons and "no time" is just the easiest excuse they can think of. In big companies I've often seen the company process prescribing such bad tools that a good TDD testing strategy is impossible to do with those tools, but they won't move away from them, because somebody in purchasing already bought 10,000 licenses for this bad tool (which is often just a bad GUI, which doesn't really help, except for selling the thing).

The worst tool was a bad GUI where you couldn't even define functions you want to use, that had slow (>1h), non-deterministic, test execution, for a unit test.