There's no problem in using olive oil, as you shouldn't get to the smoke point when frying and for oven dishes.
I use olive oil, unless I need an oil that doesn't taste of anything.
Based on this study with this conclusion: "In Spain, a Mediterranean country where olive or sunflower oil is used for frying, the consumption of fried foods was not associated with coronary heart disease or with all cause mortality"
When oils are heated to their 'smoke point' they change composition. Iirc, that doesn't mean they turn 'bad', more that the good things about that oil are removed. So for eg if you are using an expensive, extra virgin olive oil and heat it to a high point, you won't taste the benefits of that specific oil.
Some oils have higher smoke points than others (eg rapeseed oil, ground nut oils and plain vegetable oil) so if you are, say, stir-frying, it's better to use them. If you are cooking and want the flavour of olive oil, again, use the plainer oils then just drizzle a little olive oil at the end.
I have to say though that this is all based on taste/price concerns, I don't know the answer to your actual question, ie is the oil worse for you? I just know it doesn't taste as good!
We fry a lot of food. In fact most dinners are fried in some way. I'm not talking deep-frying (wouldn't know how) - more bit of olive oil to which veg and meat are added to create whatever (stir fry, a chunky sauce for pasta, a veg and bean mix, omelette, eggy bread for the kids, pancakes etc). I only ever get round to making dinner 20 minutes in advance so the oven is barely used, except to grill fish.
Anyway, I'm feeling bad about the frying. I have a vague memory that something happens when heating oil to high temperatures than makes it worse for you than, say, adding it to salad or drizzling it on fish or pizza in the oven. Is there anything in this? Or is it just the quantity of oil you consume that matters? (am I making sense??)