@Lisa1655, yes, I would definitely give a reason - it's just common courtesy. In fact, rather than necessarily declining, I would give them the chance to rectify the problem - explain that you only accept guests with a profile photo and verified ID and ask them to upload these things. If they don't do so within the 24-hour period, then you can decline. Don't forget that you start getting penalised after a certain number of declines. Also, we as hosts can't see profile photos anymore until a booking is confirmed.
Regarding reviews, everyone has to start somewhere so just because someone doesn't have any reviews doesn't mean they will be bad guests.
And I agree with @Rebecca0 that it is a bit ironic to expect people to provide a profile photo when you don't have one yourself!