On the other hand, there are countries who don't ask in advance, or even on arrival. If there is any sort of notice out about you, it's as much their fault as yours that the problem starts when you arrive, rather than being sorted out in advance.

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If you are to punish a man retributively you must injure him. If you are to reform him you must improve him. And men are not improved by injuries. (George Bernard Shaw)

And finally .... the bigger picture issue is how many countries do not believe in rehabilitation so create blanket bans on offenders (or groups of offenders e.g. by type of crime or length of sentence).

I also recognise that some countries e.g. USA have a very vigorous visa process and background checks in place which means the border guard will very rarely have more information in place. That's not true of most other countries where you fill in a visa form online or in person and there are no background checks to validate your answers.

The simple problem is that too many people lie on visa applications and then the border guards spot something amiss.
The most common is someone applying for a tourist visa and then turning up with the intention of working.  I've seen examples of cricketers arriving at Heathrow with a bag full of bats intending to be paid by a club over the summer. Likewise, a chef turning up in Spain with a bag full of kitchen knives ...

In some countries, visas do give you additional guarantees. For example, in the US, if you are approved an ESTA but then turned away by US border agents when you arrive, you have no right to appeal: being granted an ESTA online does not give you an automatic right to enter the US - the final decision is with the border guard. On the other hand, if you get a US visa, that gives you the almost undeniable right to enter the country, as the relevant checks will have been done in advance during the decision-making to grant you a visa. US border guards cannot overrule a visa decision, provided that it is legitimate, unless there are exceptional circumstances or indicators (like you being evasive or telling you them you have a bomb). and if you are refused entry then you can appeal through official channels.

I guess it differs from country to country.

We often talk about human rights on these forums, and it seems that those of us who have a criminal record seem to be cast aside when it comes to fairness. I am talking in particular about travelling to countries for a holiday. We make the effort and the expense to apply for a visa, and wait nervously for an answer, holding off plans to book flights and the trip. YIPPEE the VISA is granted so off we go and book the trip.

Then it comes to the really scary part of going through immigration at our holiday destination, where you can be pulled aside and asked about your trip. You show the VISA but the Chief Immigration officer decides he doesn't want you in the country, much to our surprise, shock and horror.

WHAT IS THE POINT OF GETTING A VISA, BOOKING A TRIP ONLY TO BE REFUSED ENTRY BY IMMIGRATION? I wish this could be changed for all countries. Apply for a visa and if granted then we can enter. Not have one set of rules for the Embassy and one for the Immigration in the country.
It is unfair and cruel.