Just so we're clear...
1. Lose your system? Buy a new system, file a police report, send police report to Nintendo, redownload all your games.
2. System stolen? Buy a new system, file a police report, send police report to Nintendo, redownload all your games.
3. Changing to a new 3DS system? Use system transfer utility up to five times lifetime per account, and contact Nintendo support about transferring thereafter (may need to send both systems to them after the five time limit).
4. Selling your system with no new 3DS to replace it? You lose all your games.
5. Don't have a system? Can't buy any games from the eShop.
Edit:
6. System break? Send to Nintendo to fix. If in warranty, no cost. If out of warranty, some cost. Keep access to all your games.
While 1, 2, and 3 (past five transfers) is a hassle that is not as good as it can be, it's completely workable for a 3DS bought in your territory. Import systems may be at issue, but then import systems for region-locked Nintendo handhelds are an issue, anyways.
So basically beyond some extra hassle (which is resolvable, but would require fundamental changes in how Nintendo handles download games, such as requiring online play to access games on another system), the only unresolvable issue (if you're willing to go through the extra hassle) is #4. If you're going a period without a 3DS, at all, you lose your games with no way to get them back.
That about sum it up?