You can see why Arsenal wanted Auba but I guess just no other club needed a fast goal poacher! But yeah the lack of any interest in Auba is surprisingly considering his scoring record. I also don't understand why City refused to get Sanchez for more than 20m and then immediately makes a 60m bid for Mahrez. OK age and wages might be a factor but Sanchez is the more proven superstar so it still doesn't make much sense if they were in the market for a new winger.
There's 3 reasons for that, first that it's hard to think of a team that doesnt have a striker as good or better than Aubameyang and that can afford paying 63M €. The second is that Aubameyang has already played Champions League this season, which makes him even less enticing for teams that may need a striker like Real Madrid. Third, he's 28. Splashing 60 million during the winter transfer market for a player that can't play Champions League and who's only going to decline in the future is not smart business.
HOWEVER, I think it makes a lot of sense for Arsenal, and I actually think Arsenal was the most succesful team in this transfer window. Arsenal isn't playing Champions League this season so that wasn't an issue, and it's very likely that they won't qualify for next season's UCL either. They also had to offload Sanchez and look for a replacement, and let's be honest Aubameyang is the best Arsenal could hope for considering their situation. Arsenal was able to get Mkhitaryan (who is extremely good and a very underrated player) and secure Özil's contract as well. I hear a lot of people say that Arsenal did poorly because they lost Sanchez but I dont think its that big of a deal, Aubameyang is just as good and signing Mkhitaryan (who's better than both) more than makes up for it.
Arsenal still needs to improve the defense, but if they manage to do that during summer they'll be in a fantastic spot. So kudos to them for doing good business last month, though I'm sure they'll somehow fuck up in summer.
PS: Speaking of clubs doing bad business, the amount of good young players Schalke lets go for free is ludicrous. Last year it was Kolasinac and Matip, and now they're losing Goretzka (their best player) to Bayern.