Character transfer issue between continents

Hello. First of all, this has nothing to do with the Shop but I was told to leave feedback here when I asked about transfering characters from one continent to the other.
While I understand why characters can’t be transfered (I understand, as in, I get that you wont do it, but I truly don’t understand why you can’t offer this service), what bothers me the most regarding this issue, is that all the achievements, mounts, looks, etc. can’t be shared with my current characters in my new server. All the time invested seems to be a complete waste of time since I can’t access anything with my new characters. I fail to see how you can send gifts to all accounts (i.e the hearthsteed), but mounts, companions, etc. that I worked so hard to get in the American server can’t be shared with the European one.
It’s sad that a company as big as Blizzard, can’t solve something like this. You need to take into account that people move and we don’t want to lose years worth of experience because of a personal decision.