I took his meaning as "assume better hardware will be available in the future", which is not what you seem to mean, and may not be as true these days anyway.
That said, when I've seen people over-engineer things (and maybe this isn't your problem, it's just what I've seen most) it's usually because instead of solving the problem in front of them, they created a flexible framework to solve a class of problems including the one in front of them. And it usually fails because they don't actually know what other problems they'll encounter - they guess and get it wrong. So their framework is flexible on Dimension X, but they actually need it to be flexible on Dimension Y.
The best advice I read on this was to never build a framework until you have at least 3 examples of the problem. Once you've got 3 examples, you have a good feel for which ways it needs to be flexible. I would add that you should also make sure you'll eventually have more than 3, because if 3 is the total number of concrete examples you still don't need a framework.
Also, it's entirely possible some smart guy/gal can give you those 3 examples before you even start building. A good product person can do that. If you have that, and they're pretty sure you'll actually get there, then go ahead and build it.
Difficulty of changing it in the future also plays into this, but I've typed too much already. :)
That said, when I've seen people over-engineer things (and maybe this isn't your problem, it's just what I've seen most) it's usually because instead of solving the problem in front of them, they created a flexible framework to solve a class of problems including the one in front of them. And it usually fails because they don't actually know what other problems they'll encounter - they guess and get it wrong. So their framework is flexible on Dimension X, but they actually need it to be flexible on Dimension Y.
The best advice I read on this was to never build a framework until you have at least 3 examples of the problem. Once you've got 3 examples, you have a good feel for which ways it needs to be flexible. I would add that you should also make sure you'll eventually have more than 3, because if 3 is the total number of concrete examples you still don't need a framework.
Also, it's entirely possible some smart guy/gal can give you those 3 examples before you even start building. A good product person can do that. If you have that, and they're pretty sure you'll actually get there, then go ahead and build it.
Difficulty of changing it in the future also plays into this, but I've typed too much already. :)