In the last couple of years...

[Brazen]

In the last couple of years I was criticized
or
In the last couple of years I have been criticized

С одной стороны, вроде есть указание времени, то есть я хотел использовать прошедшее. С другой стороны, на слух present perfect звучит лучше и в сети больше таких примеров.

[Viktoria.]

/

[Dweller]

первое правильнее
второе предполагает что критика уже закончилась

[STS]

первое правильнее
второе предполагает что критика уже закончилась

No.

"Was criticized" -- happened strictly in the past

"Have been criticized" -- still exist some connection with / relevance to what is going on now.

So it depends on what meaning is intended. However, "last couple of years" sounds like it happened somewhat recently, and possibly implies some connection to what is going on now. Therefore "have been criticized" sounds better and is usually more appropriate.

If, on the other hand, you start the sentence with "Two years ago...." then "I was criticized" would sound more appropriate.