Agree with this assessment, particularly if you consider yourself a vacation diver and therefore will only be using it underwater a couple times a year.
The tg-4 is versatile; it's waterproof to 50ft without a housing for shallow dives/snorkeling when you might not need a strobe. Or you can put it in the olympus pt-056 and attach a strobe and wet lenses.
The OP said she wants something good for land photos, too. Not that the TG-4 is not good for that. But, by the time you get the TG-4 and housing, you're in for almost 650. If you can get a Sony RX100 Mk II and a housing for around $750 - 800, don't you think it would be worth the extra money?