Thank you for your feedback regarding this. I was actually just having a conversation with the team internally about this today. The move was to make setting reminders simpler and quicker for the general user. However since the release we've had many respond with sentiments like yours.
We are discussing and taking comments like yours under advisement. The team internally will need to make a determination about how we move forward. This type of feedback is very helpful however in driving the direction of the product.
I have done as you have indicated, and it does now give you a time, however, what this means is that 'all' of our existing Tasks have a remind me of ??? minutes before a time which is already defined in the task, however, the existing time criteria can't be edited as there is nowhere to bring it up.
Instead you have to remove the "Remind Me" and then create a new Reminder from scratch whereby you are now given the choice to select a time, but to then define a prompt you have to create another reminder to shout out ?? minutes/hours before.
This adds another level of maintenance not present before, ie, in previous version you defined a Tasks date/time criteria and then you could define a remind me ?? minutes/hours before, and then you can set as many as you want but to start with you only needed ONE. Now we have to create TWO "Remind Me" as the first is for the time and the second is for the reminder.
What was the theory behind going to this kind of entry as it has made it take longer to create a task than before??
To add a time to your task please select the first Remind Me option from the task edit screen. Selecting this will allow you to set the time for your tasks.