That is a perfect mindset to have to the problem of the type "that will be a problem if we ever switch databases". However, "that will become unmaintainable in 1 year" is a "bridge" you want to cross sooner rather than later. If you have a deadline to meet, fine, but come back and fix it asap if the software is something that needs to be maintained. I really cannot explain it well, it's just something most developers realize after a while when they've had to maintain an old codebase.
They key point however is, that one guys insight shouldn't be ignored. You can take the words of wisdom and proceed to not do anything about it, but at least you know the cost down the road. All experienced managers I know personally, know the cost of umaintainable software and are more than willing to do something about it if ressources allow it. They need to, otherwise it's their ass that is in the line of fire when it cost a factor 10 to implement a new feature and bugs creep up at the customer time after time, even though they spend a factor 10 more on QA.
They key point however is, that one guys insight shouldn't be ignored. You can take the words of wisdom and proceed to not do anything about it, but at least you know the cost down the road. All experienced managers I know personally, know the cost of umaintainable software and are more than willing to do something about it if ressources allow it. They need to, otherwise it's their ass that is in the line of fire when it cost a factor 10 to implement a new feature and bugs creep up at the customer time after time, even though they spend a factor 10 more on QA.