I've been to both, all over both.
There are wide distinctions in what you'll see and how your non-diving spouse might be entertained based specifically and precisely upon which portion of these regions you might select. Huge differences between North Red Sea and South. Similar disparity amongst Caribbean Islands.
But... you have already been to the Caribbean Basin... easily arguable that it wasn't the best diving in that zone.
And... you haven't yet been to Red Sea.
This algebraic equation is pretty simple.
Because of travel distances/time, most North Americans have very little broad based experience with African/Indian continental diving. To most of us SB readers, a trip to the Red Sea or Maldives is the Holy Grail, much as EU divers see the Galapagos. The travel connections make it difficult.
An additional factor comes into play for EU Divers- they can easily (1 aircraft) and reasonably inexpensively get to very certain select Caribbean Islands. You yourself got to Nassau and GC, these are very common along with several other islands that have heavy British, Spanish or French heritages. We see a lot of Europeans anywhere along the Antiles, and most surprisingly- most of the visitors to Tobago are British Bird Watchers. (although I rank it in the Top 5 of the currently accessible Caribbean)
Ease of travel connections make the trip destinations poular, thus the reason you ended up in GC and Nassau. These are faded dive destinations that have been withered over time, but they have those strong ties and unused rooms that are sold in blocks to Euro Tours. It works well for everybody, although "better diving" lies a short twin turboprop away.
Non diving spouses can be spectacularly entertained at either GB or Nassau, as I am sure you noticed. The diving there is marginal by comparison to some of the better remaining Caribbean locales.
The Red Sea is usually divided for dive travel purposes into North and South, and for your needs, the North is the lure, based out of Sharm. You can easily do an early morning departure day-dive boat and do all of the famous "must dive" wrecks including the Thistlegorm. The wife/husband and kids can be easily entertained (at bargain prices) back in Sharm. You will be back for late dinner. There are many day boats that offer snorkel trips.
We North Americans tend to be rather xenophobic and a bit overly imaginative when it comes to the frequency of suicide bombers and similar noisy and disquieting events. We enjoy posting endlessly on Cruise Critic and Trip Advisor our questions about whether "we will feel safe" on this or that Caribbean island. For all I know, people in Lisbon fret endlessly about your localized vacation options. Somehow, I doubt they do. I have a decidedly non-Christian last name, I dress like a dumb assed American, yet somehow I really have no fear about going to Egypt. Go figure.
So... if you haven't been to the Red Sea, I would send you there. This is the place they will absolutely focus on the many unusual wrecks. The downside: They will equally ignore the flora and fauna to the same extent.
Some folks will venture off into the Red Sea's deep and look for "Mr. Grey" at certain dive sites (notably "Observatory"), but I'm thinking about some of the very few lush walls the Live Aboard type dive boats bother to take you near, seemingly as an afterthought. Lots of cool stuff, some things we consider as rare in other waters. As night fell, as all of my buddies from PADI Sport Diver UK were sitting on the top deck under starlight, sucking shisha pipes and drinking beer, I instead went for a solo night dives near/under the boat.
This is where I met my first Ocean Titan Trigger, it was not pleasant for either of us, and several pairs of the coolest thing ever, Sea Moths. The point is universal- if you go some place for the wrecks, you might want to turn your head the other way once in a while.