It's not Alex not fancying Alexandra that has got peoples backs up, it's his attitude. He's arrogant and entitled, and didn't really treat Alexandra like she's got feelings. He doesn't come across as socially awkward he comes across as rude. He completely sacked her off for Laura and then expected her to be grateful and take him back with loving arms when laura2 didn't want him, then skirted round a her questions and dumped her, whilst still insisting 5 minutes before he wanted to see how things went.
I seem to remember everyone hated Wes at the time, and still no one is voting for him and Megan, they are consistently in the bottom and are only in there because of the contestants votes. Plus whilst he treated Laura like shit, it was clear that things were a bit rocky and it wasn't that he never liked her, it was that he went off her, whilst Alex never liked Alexandra. He didn't come across as arrogant in the same way Alex does.
Ellie might have played Alex but she didn't string him along for as long as Alex did, she didn't try and manipulate his feelings in the same way or justify herself the same way Alex did. The difference between Alex and Alex3s reactions is that Alex1 was angry Ellie didn't like him, whilst Alex3 was upset Alex didn't like her, that is a huge difference.
I also think saying he's not used to the tye of women on love island is a bullshit excuse. Firstly, they are just normal people, particularly girls like Alexandra who seem genuine, intelligent just basically attractive, they can be treated the same way any woman shou be treated. Secondly he is a Dr, he deals with people of all types all day every. Medical school is hardly full of people sitting there playing dungeons and dragons every night. There are attractive, sociable people in med school and he's not a recluse. If he has slept with 30 women as he claims and had a threesome he's hardly this shy, socially awkward boy. He's just a bit of a prat, I think he's held to higher standards maybe than previous contestants because he should be empathetic and intelligent as a Dr and tbh he just isn't.