It's not really the same.
Fact is van Gaal spent so much money on di Maria and never really seemed to know what to do with him, and, eventually, got rid off him, albeit at a small loss. Regardless of net spend, or money we got back from PSG, we wasted time and money on di Maria. We quite easily could have used that money on someone else who'd still be here, today. As for you last sentence, it fully applies to van Gaal. That was piss poor management from him.
"Oh, you spent 60m on a left sided central midfielder, who had his bestest season in his career in that position, and never played him there after September?"
"Instead, you chose to play him as left winger, right winger, striker etc."
"Jesus, you're bloody useless at this football management lark" he retorts.