Someone else  has made the same comment, and though you are right, it's not really a new situation. It started  at least as far back as when they introduced the achievements, and the big players starting teleporting everywhere to attack level 1s because they are the cheapest option.

This was all fine and dandy if you had been playing a long time, had a well developed Hero, and spend oodles on the game. Not so much fun for those who were new players, or make progress at a slower pace, for whom level 1 invaders were their only possible, or most cost efficent target.

You are also probably only mentioning it now because its affecting you personally, because the game introduced some event ,or requirement, and other changes in the game encourages one hit kills.

Edited below.

The upgrades of legendary gems, which could've been introduced in stages, isn't going to help matters either.