DO is not being lazy about TOR. That are lots of "low-cost" providers who explicitly mention that TOR exits are not allowed in their AUP. These are the ones who are being lazy. Running exit nodes require knowledge and responsibility so the answer to this question cannot be a simple yes or no.
I found a handful of DigitalOcean IP addresses in the TOR directory marked as "Exit" and a dozen others who are operating non-exit relays. So you too can run one with proper precautions.
I strongly recommend running a non-exit node for a couple of months so that you know how much resources are being consumed and also to get yourself familiar with the configuration directives of
Before moving to an exit node read all the following resources carefully.
In running a Tor server, the user is acting as an ISP.
Yes the user is only "acting" they are not a real ISP which is why they are responsible for their actions just like how a VM acting as a dedicated server is responsible for saturation of its host's resources.