Not having to pay a tax is not an "implicit subsidy". This is a completely absurd way of thinking. Taxes is not some sort of fundamental law of nature, and tax exemption are not government being helpful by using its own resources to help the entity out. It's more like a bully who tells you he won't steal your lunch today (but will tomorrow). It's a nice bully, though, who'll protect you from other school bullies, and he needs to eat too. Doesn't he deserve your lunch?
Imagine a scenario where everyone is taxed, say, 10%. Then, the government introduces an extra tax of 10%, for a total of 20%, and then gives everyone a tax exemption, so that everyone pays 10% after all, just like before. Is the new tax exemption an "implicit subsidy"? Do people feel subsidized by not having to pay extra 10% on top of 10% they already pay? No, at best they are grateful that they are losing less money to a bully.
Now, imagine we start from 0%, and again introduce a new tax of 10%, and a new exemption, so that nobody actually pays any tax after all. Again, in this no tax world, is the government "subsidizing" everyone? No, that's not what the word "subsidize" mean.