Such talk (performer so and so has bad/superb technique) is just misinformed talk.
Technique is just a way of doing things for a certain purpose.
Take the high jump. Nowadays everyone jumps backwards. But before 1968, everyone jumped forwards. Both are techniques, and both give you the desired result: jumping over the bar. However you will jump higher if you do it backwards, so now everyone does it. Does that mean that jumping forwards is “bad” technique? No, it just means that there is a better technique. But in order to decide you need to have a standard of comparison. In this case the height of the bar.
Unless you have a similar standard of comparison, and unless you know what is it that the pianist is trying to achieve, you will not be able to decide if the technique is optimal or not.
Then you have the question of appropriateness. No matter how efficient jumping backwards is for the high jump, it will not work for a hurdle race, even though both events involve jumping.
Likewise, the technique to play a Bach fugue will not be appropriate to play a Chopin Ballade. Some pianists cannot manage to change their technique, so they end up specialising on a repertory (sometimes they can, but they decides to specialise anyway).
Most music critics, when they start saying so and so has no technique are usually talking through their back holes, so I wouldn’t pay much attention to it.
(A critic is to a musician what a dog is to a lamp post: The musician bring light forth, the critic urinates on it)
Best wishes,
Bernhard.