I have never had a shower over a bath or a toilet in a bathroom before we moved into this house 2.5 years ago.
I would have said the same as many PPs.
However, now I love both.
We have a glass shower screen so the little kids can splash to their hearts content. They can have a shower but have the plug in and then I can turn the water off and they can play. Even my dad who has had a bilateral hip replacement can get in and out, albeit with a little help, but it's not that hard.
A second loo is a benefit to renters. If someone is in the bathroom and another person needs to go, then there's your other loo.

So no, don't think it's a disadvantage. If I was looking at renting I'd like it.