I think it's physically impossible to have a wallet for every coin. For example, turtlecoin, a very new coin, already has a blockchain to sync at 4 gb.

Bitcoin has a blockchain of 150 gb.

If you got a separate wallet for each coin, you're looking at syncing over 1 TB....

That said, it's safer to get a new wallet for each coin because of mitigated risk. If one wallet gets hacked, at least you don't lose all your eggs because they weren't in one basket.