And work isn't a decider for us in where we chose to live, it didn't play a part as hubby works from home.
Honestly, you rave about Port Noarlunga and beachside living but its not for everyone. And most won't live across the road from a beach. For many they may live on the cusp of the suburb bordering with the next suburb inland, so its not really beachside living as you want us to think. Its suburban living with a drive to get to the beach. While I think Port Noarlunga a nice place, the shops there are good for a browse, I find it lacking scenery that *I* appreciate. Hills, trees, wildlife and more. School options were a factor in where we chose to buy and the suburbs you mention didn't have a draw for us in that department, at least not state school wise. Plus that big road (well, now two) running through or close to the suburbs there don't appeal either. I grew up in a coastal area in the UK, lived near one as an adult and its not important to me to live near one, not then, not now. I don't wish to spend my free time sitting on a balcony overlooking a carpark before the water. That isn't fun to me. Its boring as anything. I'd rather be out in my garden, pottering, relaxing, seeing all the wildlife in it and other things. If I want to go to the beach, I grab the beach bag and hop in the car and am there in 10-15 minutes.
There are plenty of other options for people that are not the southern coastal suburbs. The OP can investigate the more city based ones to see if they like them and also visit further out ones. They may even head more inland to a more central suburb if it suits, fair play, some lovely places nearer the city IMHO. Hopefully they will find something they like that suits all their needs. I think Henley and Grange are decent suburbs to consider as a starting point for them and many live there happily.