Nah, unity is/was a good engine. The reason why it has a bad reputation is for the same reason that Game maker used to have a bad reputation. Almost everyone who’s learning how to make games uses Unity because it’s easy to use, is extremely well documented, and has a massive store full of add-on scripts, programs, model sets, etc. As such, all the poorly optimized games and 0-effort asset flips end up being made in unity (though I’ve seen some unreal games that make even the most poorly optimized Unity game look good). The result? Even though there are a number of high-quality, highly-regarded games that use unity, it has a reputation for being a shitty engine.
Don’t believe me? Keep an eye on Godot or Unreal. If unity sticks to their new license, then it’s highly likely that one of those engines will become the new “newbie engine” and gain a reputation for being shitty.