To be fair BA, it was eight years ago. Tanya isn't even in the show anymore. There's "outrage" over the Beales and Mitchells condemning Max to 20 years inside because it's a recent/current and ongoing storyline. Eight years from now I don't imagine it will still be a regular topic of discussion. However, there has been a few threads on Tanya recently (should she come back? etc) where I've seen her criticised for what she did to Max.
I think this was more so shocking because of the number of characters behind Max's torment. A few of whom had never been written as cold as they were in this storyline before it. With the burial you had one woman on the edge working with the local nutter. Even then Tanya felt remorse. Her conscience got the better of her and she got Max out of the situation she'd put him in. The adults in this situation would've probably let him suffer for a full 20 years if Bobby hadn't taken it out of their hands.
What Tanya put Max through was worse though. I'm sure even Phil would draw the line at burying somebody alive. It's a barbaric stunt. The constant feeling of dread, claustrophobia etc. But I will give her some credit over this lot for ending his suffering (in generic terms, I think the suffering caused by Tanya was probably worse).
However, while not as bad as the coffin encounter, I don't imagine prison has been a breeze either. Max will have felt dread and anxiety at points during his time there and at times these emotions would've been heightened. He told Jane last year that he was getting a hard time due to other prisoners thinking he'd killed a young girl. The actions of Ian, Jane, Phil, Sharon, Lauren etc are still cruel and wrong regardless of Max having suffered a horrific experience beforehand.
It's Max's prerogative who he chooses to forgive/seek revenge on just as its up to each individual viewer what injustices they choose to be outraged by. People are always going to be lenient or harsh depending on their general feelings towards the characters involved.