This seems to be a question that pops up from time to time so I guess a lot of owners feel that they should be spending more time interacting with their dogs. I'm also someone who wonders if I'm getting the balance right.
You don't say how much time you spend with your dogs but as long as they're walked regularly, fed regularly, played with regularly and have a chance to be with the family, even if that's just sitting in the same room, I would think that's fine. Also for most dogs, being left for long periods is a problem, but you say you're at home a great deal.
I walk my dog twice a day, she's small so the walks aren't as long as I'd spend with a bigger dog, but we do have to have two walks otherwise she get very restless. I vary what we do during the morning, off lead, walk: bit of ball chasing, bit of training, and just sniffing about. The second walk is usually on lead.
Then during the day we have a bit of playing and just general fussing from time to time: pat her when I walk past her, throw her ball if she wants,that sort of thing. She mostly tends to be awake during a lot of the evening so we'll have a bit of calm play and a bit of tummy/back rubbing type interaction. Sometimes though she'll just sleep all evening.
She spends quite a bit of the day dozing and wandering in and out of the garden. I'm retired, so like you I'm home a lot of the day but I certainly don't spend my days entertaining her and I doubt many owners do.
Dogs need to be able to sit/lie and be calm, and they need to learn how to be alone for short periods. Over stimulating them or over exercising them can result in a dog that's always wound up and doesn't know how to relax.
I always feel a bit guilty when I leave her alone, again, I think that's common to a lot of dog owners.
The fact that you're worried that you're a bad dog owner probably means you're not and you're worrying about nothing.:)