Amsterdam is pretty safe. As in any big city, you'll get pickpockets, but I walk around central Amsterdam on my own at any time.

WE had no issues a few years ago.
We visited Alkmaar, DeRijp, Azande Schans,
Rijks Museum and Van Gogh( Stary Night in NYC)
Boat ride of couse.
Purchase tickets on line for Museums and go to different entrance.
Super Trip!

As a tourist you are extremely unlikely to end up in one of the sketchier areas of the city. Just keep your wits about you as you would anywhere.

Amazing that "tourists" then proceed and visit one of the most sketchy areas of Amsterdam voluntarily.

True enough.

Which is where?

I think they are talking about the red light district (to the south east of Centraal Station, on Oudezijds Voorburgwal and Oudezijds Achterburgwal). It is one of the major motivations for a lot of tourists.

Lavandula

And one of the sketchiest areas in town.

The pro tip here, is to visibly look out for bike traffic as you step onto the bike path, ie, with a body movement, and to make eye contact with cyclists at intersections. You'll notice that there is a lot of silent negotiating and give and take is going on. Dutch people on bikes learn this at an early age, and they are ingrained habits, Tourists who are not used to this much intensity in bike traffic need to learn.

Here's a video to give you an idea.

I see no reason to not take your after dinner walks as long as you are careful and use common sense just as you would in any city. You can get some dodgy people around the train station and other areas as mentioned but they are very unlikely to cause you problems beyond annoyance.

One way to take the pain out of this is to avoid RLD and other sleazy tourist spots like Leidseplein and Rembrandtplein.

Amsterdam is one of those cities where if you aren't familiar with it you can take a turn and find yourself in a very different environment. This was the middle of the day but when I walked from a more central area out to Tropenmuseum (maybe this was Oosterpark?) I most definitely stumbled upon day time drug users laying around in a park. Even as a visitor, yes, you could end up in places you probably don't belong.

The OP's post/ trip was back in May.

I read many people on NL threads who want to cycle in Amsterdam, "to be like the locals". If there is an opportunity to dissuade them, I'll grasp it.

Was mainly replywalkinaround who raised "bike traffic".

It wasn't me who raised bike traffic but it's a fair point. And like many I missed that the thread was older.

I've walked near the small Red Light district over several decades, night and day. It's the same as any big-city core: Stay where other people are and no dark-alley shortcuts.
Bicycles do give way to each other (and to the trams) but not to pedestrians. The most dangerous thing a tourist can do in Amsterdam is to step into a bike lane when crossing the street. Some of the peddling is a lot more hectic than in the YouTube video. And most of the bikes are sturdy rather than sleek racers, often banged up and maybe retrieved from a canal bottom.

The expectation is that pedestrians are aware of bike traffic and "join in the game" as it were. However, tourists are often not aware that bike paths are bike paths and will use them as sidewalks. This does not go down too well with the locals.