Yes, you can probably make more by adding more pressure than nagware did. But you’re doing it at the expense of being pro-user. I do think it’s reasonable to be less friendly than that, if it doesn’t work for you.
You can probably make even more than free trials by getting people into a monthly subscription, making it harder to cancel, and/or making it so it’s easier to forget that they’re being charged, etc. There are many ways to enrich yourself at the expense of others. And many companies seem to have justified each of these to themselves.
No, that's your mistake as a software maker. User behavior is user behavior.
If you're losing potential paying customers because you lock them out of the trial because they didn't come back to it for a week, it's your sales that will suffer.
Business are risk averse. They don't care about that as much as the real worst case: you become winRar and you have a lot of paying customers that never convert because you gave away too much of your product. It's really hard to put thst genie back into the bottle.
A 14-day (or 7, or 30 day) trial is actually perfect for this situation.
But you can't make everyone happy. If someone is starting the trial and then not using the software for a week or month, that's their mistake.
There was a time when nagware software was popular: You got to use it for free, but it would nag you with a popup or delay every once in a while asking you to purchase it. You can still occasionally find software with this model, but most developers quickly learned that the more leeway you give the free trial users, the less likely they are to buy it.