For one thing, many of my professors (in fact, probably all of them) were very theory focused, and had very little experience implementing electronics. I think they figured that practical topics like this were too specific to lecture about, and we'd pick it up on the job anyway. I'd have to assume that mindset is not wholly exclusive to my undergraduate degree.
For another thing, I find that commonly, large employers are frequently not doing much to train their new grad EEs, or even let them near much design work. As a result, they miss out on practical experience that would teach them about concepts like decoupling.
Same! I didn't realize you needed them until I entered industry. I think that's a little disappointing - it's a very simple explanation, just one that most professors don't choose to spend time on.
I'm trying to put together a good demonstration of why you need decoupling capacitors in a lab setting. Best one I can think of is paralleling a bunch of inverters with no decoupling caps, and then measuring the current draw on the rail using a shunt resistor.