As I understand it, they only deleted old threads. So, you're right, it was providing free support, but only for old versions of their software, so they didn't make any money out of that. The theory is, if people struggle with those then they might be pushed towards their newer versions (where forum threads haven't been deleted) and so they have to pay up.
That's not sound reasoning though, business-wise. Old customers are going to stick with old software. Keep them! If they're growing at all then they're going to need new seats which means you can sell them some. Maintaining the old versions (with all that free support on the forums and one part-time engineer to fix bugs) is cheap.
On the other hand, if you cut off the old customers and try to force them to retool their entire workflow to your new software then you risk driving them over to a competitor. Why would you do that? It's better to have customers on your old software than alienate them entirely.
I think with Autodesk's size it's easy to forget what they actually do: build tools for professionals in a variety of high-end niches (engineering, architecture, graphics). This is not a mega-growth industry, it's a conglomeration of lifestyle businesses. Professionals like this demand first class support and workflow stability. They absolutely will get alienated if they have to waste hundreds of engineers' hours retraining and retooling for your new product and will look at that as a prime opportunity to jump to a competitor who treats them better.
That's not sound reasoning though, business-wise. Old customers are going to stick with old software. Keep them! If they're growing at all then they're going to need new seats which means you can sell them some. Maintaining the old versions (with all that free support on the forums and one part-time engineer to fix bugs) is cheap.
On the other hand, if you cut off the old customers and try to force them to retool their entire workflow to your new software then you risk driving them over to a competitor. Why would you do that? It's better to have customers on your old software than alienate them entirely.
I think with Autodesk's size it's easy to forget what they actually do: build tools for professionals in a variety of high-end niches (engineering, architecture, graphics). This is not a mega-growth industry, it's a conglomeration of lifestyle businesses. Professionals like this demand first class support and workflow stability. They absolutely will get alienated if they have to waste hundreds of engineers' hours retraining and retooling for your new product and will look at that as a prime opportunity to jump to a competitor who treats them better.