I've not stated that di Maria has had a good season, all I've said is that, given the circumstances, he's not been as awful as YOU keep stating. Yes, his performances haven't been great, yet he's still contributed. Does that not count for anything? According to you, no, it doesn't matter. You have to be doing something right if you can still bag assists every two games or so and a few goals in between. Or is it all luck?
West Brom scored a very lucky goal against us, last week. However, do you think they care? You think they felt guilty after being crap all game and winning? They won and that's all that matters in the game in football, especially when the stakes are high.
What can you can analyse from his last 6 or 7 substitute performances? During his time as a starter from September to March, he wasn't anywhere near as good as last season, yet he scored and assisted some incredibly important goals and performed well (on a rating scale of about 6/10, with the odd 7/10) every 2-3 games.
I, too, expected much more from him, but I can appreciate what he has done for us. We needed CL, next season, and he's helped get us there. That, for me, is all that matters, right now.