1. Those who take short cuts in design, construction or manufacturing which can be common to save costs. While cost is a valid concern in engineering, I believe things should be engineered for durability, sustainability, etc. to last in a variety of circumstances & environments.
2. Those who lack critical thinking in engineering design, etc. This is probably more common than not (i.e., many lack the skills or desire to think critically). In short, this requires engineers to consider the "what-if" circumstances and "what else" (other) considerations.
3. Those who do not adhere to engineering ethics. Like some other professions, professional engineers are bound by an oath (called a Creed according to the National Society of Professional Engineers) to conduct themselves and perform their engineering responsibilities according to ethical principles because those designs may involve lives, property, etc. Many college curriculums require a course in engineering ethics as they should. However, there can be cases where some either forget or overlook this considerations in the name of time, profits, etc.
One thing I have learned about engineering is that different industries have very different cultures and working styles. Since I work for a publicly traded medical device manufacturer, my pace of work typically picks up around very important deadlines or dates like the end of our fiscal year. So even when things get busy, it's typically somewhat predictable, and I have good work/life balance the rest of the time. My husband, on the other hand, who is a civil engineer, worked for a private company that did industrial site development. I described his word as "feast or famine" - they either had an active contract and everything had to be done NOW, or he didn't and things were very slow. This can be preferable for some people, but I would hate working in that type of environment! So, if you find yourself in an environment that doesn't work for you, know that you may be able to change it by moving to a different company or industry.